Live Coverage as Voters Head to the Polls

CHARLOTTE, N.C. — After all the debates and town halls events, after the candidate surges, withdrawals and endorsements, voters finally had to make a choice.

But for Democrats who long hoped for the field to narrow and the choices to sharpen, there was still uncertainty at one suburban precinct outside Charlotte, N.C.

Voters arriving in a light rain at Myers Park High School preferred various candidates, but nearly all expressed doubts about whether they had made the right choice. The hesitation reflected weaknesses in the field that 10 debates and four indecisive state caucuses and primaries exposed, not to mention the prospect of facing the break-all-the-rules style of President Trump, who on Monday night in Charlotte mercilessly taunted Joseph R. Biden Jr. for his age and verbal misfires.

Read more In North Carolina, anxiety over who can beat Trump.

“I’m worried about our country, I don’t think we have a perfect candidate this time — we don’t have a Barack Obama,” said Justin Faircloth, a real estate investor and musician. He made up his mind just on Tuesday morning to vote for Bernie Sanders. But doubts lingered.

“I’m concerned with Biden, Warren or Sanders, whether they can really make it happen," he said.

Sally Higgins, a lawyer, decided on Sunday night to vote for Elizabeth Warren, after wrestling over whether she was electable. “I worry about sexism in our electorate and our media,” she said. “Like everybody else, I’m worried about who can beat Trump.”

Emily Protsyk, a stay-at-home mother, had favored Pete Buttigieg, who recently dropped out and endorsed Mr. Biden. “I really like Joe Biden,” she said. “I really liked him on Oprah’s “Super Soul Sunday,” but I’m not comfortable with his presentation.”

She settled on Michael R. Bloomberg, “after a few walks around the block with my neighbors."

An Indian-American couple, who asked that their names not be used because a senior executive in the husband’s firm is working for the Bloomberg campaign, also decided at the last minute.

“Last night I was all about Bloomberg because of his gun control,” said the wife, who had decided on the drive over to vote instead for Mr. Biden. In the end, she expected the race would come down to a two-person contest between Mr. Biden and Mr. Sanders, who she believed was too far left to win. “I don’t want to take away votes from Biden by voting for Bloomberg,” she said.

Her husband went with Mr. Bloomberg. “Unfortunately, Biden is old and forgetful," he said.

“At the end of the day, we’re out for one thing, which is our side to win this thing.”

MIAMI — Michael R. Bloomberg ordered Cuban coffee in Little Havana on Tuesday but without the beverage’s signature sugar kick. “Sin azúcar para mí,” he said.

His use of Spanish did not end there.

A few minutes later, when a reporter asked him about the Texas primary, Mr. Bloomberg interrupted her. “Tejas, we’d say here.”

Read more Texas or Tejas? Bloomberg deploys his famous Spanish in Miami.

“That’s Spanish for Texas,” he explained. “You’re in a Cuban neighborhood. So you’ve got to know the audience.”

Mr. Bloomberg seemed delighted to be in sunny Miami, highlighting that New York, the city he led for 12 years as mayor, also has a large Latino population. And he seemed happy to dish one-liners about his opponents.

When asked if a third-place finish in Tuesday’s contests would be acceptable, Mr. Bloomberg asserted, “There are only three candidates. You can’t do worse than that.” Then a reporter reminded him that Elizabeth Warren remained in the race, not just Bernie Sanders and Joseph R. Biden Jr.

“I didn’t realize she’s still in,” Mr. Bloomberg said. “Is she?”

Walking to his nearby campaign office, Mr. Bloomberg, who has not held as many events with voters as his rivals, saw women inside an art gallery waving hello. He stopped and greeted them.

But he had less time for supporters holding campaign side outside his office door. As Mr. Bloomberg walked by, he promised to “shake hands later.”

Bernie Sanders’s team was caught off guard on Monday by how swiftly moderate support coalesced around Joseph R Biden Jr. after the former vice president’s commanding win in South Carolina over the weekend.

During a whirlwind 24 hours, former Senator Harry Reid of Nevada, Amy Klobuchar, Pete Buttigieg and many others backed Mr. Biden. And by Monday afternoon, everyone on Mr. Sanders’s campaign recognized that there were new dynamics at play.

“We always anticipated that there would be consolidation of an establishment side,” Faiz Shakir, Mr. Sanders’s campaign manager, said Monday night in an interview. “It’s one thing to know it’s going to happen, and it’s another thing to watch it happen so very quickly.”

Read more The Sanders camp didn’t foresee how quickly Biden would amass support.

He added: “Because of the swiftness with which it moved, it’s becoming clear that in order for us to win this nomination, that road clearly flows through Joe Biden.”

After investing nearly $15 million in ads in Super Tuesday contests, as well as Nevada and South Carolina, a super PAC backing Elizabeth Warren is planning not to invest in any of the contests next week, according to a spokesman.

The decision will allow the super PAC to restock its coffers, and potentially allow Ms. Warren to reassess her candidacy, depending on the results on Tuesday evening.

There are 352 delegates at stake next Tuesday. Michigan, the biggest state on that day’s map, is where Ms. Warren plans to watch the results roll in tonight. The senator has bought television time in several of the states up next week, including Michigan, Washington, Missouri and Idaho.

Read more A Warren-aligned super PAC says it will skip the March 10 states.

The super PAC does plan to make more ad buys in states that will vote on March 17, the spokesman, Joshua Karp, said. Persist PAC, which formed in mid-February, may also need to return to donors to ask for more funds after spending so much so quickly.

Throughout 2019, Ms. Warren had been one of the most outspoken critics of super PACs, which can raise and spend unlimited sums of money. But after the pro-Warren group formed, she declined to disavow it.

Super PACs must operate independently and cannot legally coordinate with campaigns. But by publicly declaring their advertising plans to the media, they are able to telegraph tactical decisions to their candidates.

WASHINGTON — The American government is combating chronic disinformation from Russians and other foreign actors but observed no spike of activity ahead of Super Tuesday voting, officials said Tuesday.

As voters went to the polls, American officials stepped up efforts to both raise awareness of foreign influence campaigns and try to reassure the public that voting systems remain secure. In a joint statement on Monday, Secretary of State Mike Pompeo and other officials warned of the dangers of foreign influence on the electorate.

While Russian disinformation campaigns have received the most attention, officials have said that other adversaries including China and Iran are also trying to influence American voters or heighten existing divisions in the United States. Their broader objective is destabilizing democracy, a senior Department of Homeland Security cybersecurity official said Tuesday. To counter that, administration officials have tried to educate the public on how to identify disinformation campaigns. The agency uses a debate over whether pineapple belongs on pizza to illustrate how other countries can amplify disagreements among Americans.

Read more U.S. officials increase efforts to warn voters about foreign election interference.

Influence campaigns attributed to Russia constantly change, prompting the administration to work with technology companies to uncover them. By identifying the issues that foreign powers are highlighting at any given time, American officials can help campaigns and the tech companies take action, the official said.

While foreign powers are also constantly investigating computer systems around the United States, the government has not yet detected any effort to hack election systems. On Tuesday, the senior official said, all lights were continuing to “blink green.” Any technical glitches reported earlier in the day appeared minor.

With its large trove of delegates and the polls showing a tightening race, Texas voters could play a significant role in shaping the Democratic primary on Tuesday.

But down ballot, there are important congressional primary contests that will sort out crowded races.

The Biden campaign is hoping Amy Klobuchar can deliver some votes for him in Minnesota, or at least slow a Sanders runaway in the state.

Hours after the now-former presidential candidate announced her endorsement of Mr. Biden at a rally in Dallas, the Biden campaign cut a television ad of her remarks, aiming to get it on air in Minnesota as voters hit the polls in her home state.

Before she made her endorsement, Ms. Klobuchar darted off to a studio to cut a radio ad for Mr. Biden, which the campaign put on radio stations around Minnesota on Tuesday morning.

Read more Klobuchar hits the airwaves for Biden in new TV and radio ads.

“Here in Minnesota, we know that what unites us is so much bigger than what divides us,” the senator says in the 60-second ad, as a warm guitar beat and chimes provide an uplifting soundtrack.

She contrasts the vice president with the other nomination-seekers: “Unlike other candidates, he gets results. He worked tirelessly with President Barack Obama to pass Obamacare and lead the Recovery Act.”

The Biden team, which had not advertised in Minnesota at all for most of the campaign, began a relatively small $55,000 ad campaign in the state on Monday, according to Advertising Analytics, an ad-tracking firm.

Before Ms. Klobuchar dropped out of the race on Monday, she seemed poised to win her home state, with recent polling showing her ahead of Mr. Sanders, but not by a margin large enough to meaningfully deny him delegates. She remains immensely popular in Minnesota as a home-state senator, and her endorsement for Mr. Biden could help swing some toward his campaign.

Now that Ms. Klobuchar is out of the race, Minnesota could become an important delegate grab for Mr. Sanders, who held a large rally in St. Paul on Monday night.

Minnesota, however, has a lengthy early-voting period; Ms. Klobuchar voted on the day of the Nevada caucuses in February, presumably for herself, and there are likely many in the state who have already cast their ballots.

12:12 p.m. March 3, 2020

The New York Times

A woman watched from above as Senator Elizabeth Warren and her husband, Bruce Mann, were swarmed by supporters as they headed to vote at Graham and Parks School in Cambridge, Mass., on Tuesday.

BURLINGTON, Vt. — Bernie Sanders gave a hug. He delighted at a tray of cookies at a bake sale. He accidentally locked his wife, Jane Sanders, out of the family Subaru.

After a frenetic week of campaigning across the country, Mr. Sanders was back home in Burlington on Tuesday morning. Nothing was on his schedule except a brief jaunt to his local polling place. He drove himself there, in a light blue Subaru Forester. On its rear window was a Bernie 2020 bumper sticker.

“I want to make sure we get at least two votes in Vermont!” he said as he and Ms. Sanders made their way into the local community center to cast their ballots.

Read more Sanders drives himself to the polls.

“Nice seeing you both,” a woman at the check-in said.

“Hey, I love you,” another crooned.

He and Ms. Sanders sat next to each other in the voting booth. The senator got his two Vermont votes.

Then the couple made their way back outside, a crush of photographers angling for the best shot. He paused briefly to make a statement, a stump speech his fellow Vermonters had heard countless times before.

“We are determined to defeat the most dangerous president in the modern history of our country,” he said.

He told a reporter that he had learned in Vermont how to build a coalition of voters. “That’s what we did in Burlington,” he said, “and that’s what we’re going to do nationally.”

He said he had “slept well.”

Then he got back into his car. The passenger door remained locked.

“Bern! Bern!” Ms. Sanders shouted, trying to get in, too.

He unlocked the door, and she got in. He backed the car slowly out of the parking spot, and they drove away.

MIAMI — The Florida primary is not until March 17, but Michael R. Bloomberg said he would spend Super Tuesday campaigning in Miami, Orlando and West Palm Beach because he intended to stay in the Democratic race until November — even if his only way to victory is through a contested convention.

“I don’t think I can win any other way,” he said Tuesday morning at his campaign office at a small strip mall in the Little Havana neighborhood of Miami. Of the 14 states going to the polls on Tuesday, Mr. Bloomberg acknowledged: “I don’t know that we’re going to win any.”

He seemed irked by questions about whether his remaining in the race was helping Bernie Sanders to the detriment of Joseph R. Biden Jr.

Read more ‘I don’t think I can win any other way,’ Bloomberg says of a contested convention.

“I’m not helping Bernie Sanders — I’m trying to help myself,” Mr. Bloomberg said while walking out of Azucar, a Cuban ice cream parlor with a portrait of Celia Cruz, the salsa queen, painted on the wall. He ordered a cone of café con leche ice cream, a local favorite.

“Why don’t they coalesce around me” instead of Mr. Biden, Mr. Bloomberg asked of moderate Democrats.

Manny Diaz, the former Miami mayor who is a co-chair of Mr. Bloomberg’s national campaign, introduced him as the anti-Sanders, casting the Vermont senator as a “socialist” not to be trusted because of his past praise of Fidel Castro’s Communist revolution in Cuba.

“Demagogues with beautiful words, they promise revolution but deliver nothing,” Mr. Diaz said.

Cheering Mr. Bloomberg was Robin Smith, 53, who said she switched her voter registration from Republican to Democrat three weeks ago to vote for Mr. Bloomberg.

“I think there are enough of us that are willing to vote for Mike,” she said. “Perhaps Biden is splitting the vote.”

As Mr. Bloomberg may know, brokered conventions have indeed happened before. But it’s been nearly 70 years since there was a true nominating fight on the convention floor.

DALLAS — The endorsements came just in time.

About 12 hours after Amy Klobuchar, Pete Buttigieg and Beto O’Rourke all threw their support behind Joseph R. Biden Jr., voters in downtown Dallas were citing the sudden unity as their reason for supporting the former vice president.

“I fully intended to vote for Pete, and then when he dropped out, I was like, OK, Klobuchar seems like a good idea,” said Haley Walton, 26. “But then she dropped out, so it helped that they both endorsed Biden. That kind of made the decision easier.”

Read more In Dallas, voters point to the power of an 11th-hour endorsement.

“I was on my way to Pete’s rally when he dropped out, actually,” added McKenzie Phillips, 26. “We were about to leave for that, heard the news, and then when Amy Klobuchar backed Biden, that was the decision backed up for me.”

They both said that while they liked Bernie Sanders, especially many of his ideas, they did not think he was the best candidate to take on President Trump, and worried about some of his supporters.

With a slow but steady stream of voters — 130 had voted at this precinct in the Democratic primary as of 9 a.m. — many who had been weighing the candidates said they settled on Mr. Biden in only the last 48 hours, as their preferred candidates dropped out and threw their support behind him.

Garrett McGrew, 35, and Richard Rivas, 37, also made late decisions, interpreting the endorsements from Mr. Buttigieg and Ms. Klobuchar as signals to vote for Mr. Biden. But they were confident in their new candidate, even if he was going to have to make up lost ground against Mr. Sanders.

“Biden can catch Bernie,” Mr. McGrew said. “I think he’s a great candidate and I think he reaches out to a lot of people who might not be the Bernie supporters, but he’ll definitely get some traction with the rest of the voters.”

Others were caught in the hold-your-nose-and-vote phase of a winnowed primary.

“I voted for Biden, but it’s not who I wanted to vote for at all,” said Samuel Mortimer, 32. “But I was voting for anyone other than Bernie. He’s a whiplash candidate, and it’s going to be another four or eight years if he wins of ‘what are we going to do to defeat Bernie and everything he does,’ just like they did to Obama. He’s not the healing candidate and he’s not what the nation needs.”

Supporters of Mr. Sanders, however, like Pete and Maggie Hyndman, saw Mr. Sanders as the most electable candidate.

“It was being able to recognize that the candidate should reach out to other segments of the population other than the mainstream,” Ms. Hyndman, 31, said. “And I think that Bernie has shown that.”

In the Northern California county where a mysterious case of the coronavirus had been reported and dozens of people were quarantined, a top election official said the county bought gloves for poll workers and expanded curbside ballot drop-off points for Super Tuesday.

“You can do your whole voting experience right from your car,” John Gardner, the assistant registrar of voters for Solano County, said in an interview on Monday night.

On the other side of the country, a Massachusetts election official said the state would allow patients who are quarantined at home to have someone pick up and return their ballots to local election offices, the same accommodation made for voters who are hospitalized.

Read more Coronavirus concerns prompt extra precautions by election officials.

And in Colorado, the state directed counties to provide hand sanitizer and to wipe down voting machines after each use at polling centers, according to a state election official.

As millions of voters go to the polls on Tuesday in 14 states, the specter of the coronavirus outbreak has become another quandary for election officials already contending with misplaced ballots, voting irregularities, data breaches and challenges to the integrity of the process.

“We’ve put out guidance that voters may use their own pens, and we’ve also asked local election officials to provide disinfecting wipes to poll workers so they can regularly wipe down the booths and pens,” Debra O’Malley, a spokeswoman for the secretary of the Commonwealth of Massachusetts, said in an email on Monday night.

Ms. O’Malley said a state law that allows voters who have been admitted to a health care facility within five days of an election to have someone bring them a ballot and return it had been extended to self-quarantined patients.

Massachusetts uses only paper ballots, according to Ms. O’Malley, who said that pens in voting booths would be the only shared item handled by voters.

In California, which has the most delegates of any state, election officials noted that the state had been making accommodations for so-called no excuse absentee voting since 2008. Historically, to get an absentee ballot in many states, a person had to be out of state or unable to visit the polls for medical reasons.

Sam Mahood, a spokesman for the California secretary of state’s office, said in an email on Monday night that more than 75 percent of voters in the state had received vote-by-mail ballots for this election.

“We, of course, will monitor any public health alerts from state or federal officials that could impact election administration,” Mr. Mahood said. “Right now there are no indications of any disruptions to California’s March 3, 2020, presidential primary.”

In Colorado, every ballot cast is paper, and 97 percent of them are mail ballots, Judd Choate, the state’s director of elections, said in an email on Monday night. The remaining 3 percent of ballots are cast in person using a ballot-marking device, Mr. Choate said, and poll workers are instructed to clean off those machines after each use.

Last week in Solano County, which is northeast of San Francisco, public health officials announced that a woman from the county with no clear ties to any previous case or overseas travel had tested positive for the novel coronavirus.

The county said it was monitoring dozens of people with whom the woman had interacted, including relatives and co-workers. Among them were at least 124 health care workers, a nurses’ union said.

“We haven’t even heard concerns from our poll workers about this,” Mr. Gardner said. “Solano County is 80 percent vote by mail.”

Still, at all 92 voting precincts in the county, voters can pull in to a designated parking space, call a phone number on a sign and have an election official come out to their car to collect their ballot, Mr. Gardner said.

In addition, the county will have three locations entirely dedicated to curbside drop-off, instead of the two it had in the past, he said.

“They unroll their window, hand them their ballot,” he said.

Mr. Gardner said the county had not had any difficulty recruiting poll workers for Super Tuesday. Still, it has stocked up on hand sanitizer, disinfectant wipes and gloves, which it has not used in a while.

“We have gloves for our poll workers if they’re not comfortable,” he said.

LaTosha Brown, a founder of Black Voters Matter Fund, endorsed Elizabeth Warren in the Democratic primary just hours before voting was to begin in Super Tuesday states.

In the announcement, which she made Monday night on Twitter, Ms. Brown said it was time for progressives “to stand up and fight for what we believe in.”

“The moderate & centrist wing of the Democratic Party got us in this mess,” she said. “We need FRESH ideas and New energy to move America forward. We need to energize our base. That’s why I am proud to endorse @ewarren!”

Read more LaTosha Brown, a founder of Black Voters Matter Fund, endorses Warren.

More than 3.5 million Californians have already cast ballots through vote-by-mail or other methods. But for everyone else in the state — especially those with a few last-minute questions before they head to the polls — we put together a little Super Tuesday guidance.

In this morning’s edition of our California Today newsletter, we explain how to find the nearest place to vote and why it is going to take so long to get definitive results tonight. And while we can’t tell you who to vote for, we rounded up some helpful features from local news outlets that you can consult as you make your decision.

Lots of other New York Times reporters will be on the ground in California today. We hope to see you out there.

Read more A little Super Tuesday help for Californians.

A special edition of California Today

Amy Klobuchar said on Tuesday that she was not pressured by anyone to quit the Democratic primary race and pushed back against the idea that members of the so-called establishment were conspiring to stop Bernie Sanders from winning the nomination.

In a jampacked Tuesday morning interview on NBC’s “Today” show, Ms. Klobuchar said that the decision to end her quest for the Democratic nomination “was a decision I made,” adding that “there literally was no push from anyone.”

Asked by Savannah Guthrie whether members of the Democratic mainstream were trying to collectively “crush” Mr. Sanders and his movement, Ms. Klobuchar said she did not see herself, Pete Buttigieg or Beto O’Rourke — all of whom endorsed Joseph R. Biden Jr. on Monday — as part of the Democratic “establishment.”

Read more In new interview, Klobuchar says she was not pressured to exit the race.

“I look at us as new leaders for the party,” she said. “And we’re basically saying, ‘We’ve got to win here,’ and that’s why we’re supporting Joe Biden.”

“None of us had talked to each other,” she said of herself and other candidates who, like Mr. Buttigieg, decided to drop out. “We came to our own decisions.”

Ms. Klobuchar also rejected the notion that Mr. Sanders could not defeat President Trump in a general election, but added: “We want to win big.”

“You want a candidate that not just builds a coalition of fired-up Democrats, which we’ve got, but also brings in independents, moderate Republicans,” Ms. Klobuchar said. “That’s how we won back the House of Representatives, and that’s what Joe Biden can do.”

Ms. Klobuchar said she had not discussed the possibility of serving in a Biden administration with the former vice president and deflected a question about whether she would consider being Mr. Biden’s running mate.

“I’m just doing my work right now,” she said. “I’m one day out of having left my own campaign.”

Especially today, with the news cycle moving at a breakneck clip, last-minute developments can change the course of a race. When that happens, it can render pre-election polls outdated — sometimes before they’re even released, or just after.

Case in point: Super Tuesday.

Since most of the latest state polls came out a few days ago, Joseph R. Biden Jr. has won the South Carolina primary; he’s racked up a slew of high-profile endorsements; and three of his most prominent rivals — Pete Buttigieg, Amy Klobuchar and Tom Steyer — have dropped out. It leads to a lot of open questions.

Read more A lot has changed since polls were taken. They still tell us something.

Will Mr. Biden’s landslide victory in South Carolina be enough to turn back Bernie Sanders’s momentum, particularly among black voters, and particularly in Southern states? Have the endorsements of figures like Senator Tim Kaine and Harry Reid, the former Senate majority leader, made an impact? And now that three candidates — who together commanded about 15 to 20 percent of the vote in most nationwide polls — have departed, where will their supporters go? There’s reason to doubt that they will flock to Biden en masse.

We won’t know the full answers to any of these questions until the results come in tonight. But polling can still tell us a lot about which groups are most likely to support which candidates, and who seems to have the strongest shot in major states.

Mr. Sanders remains the race’s front-runner, and he holds a commanding lead in the biggest state, California. He’s also likely to perform well in the second-biggest state, Texas, and in Colorado and Utah.

Mr. Biden’s strongest opportunities are in the South, where heavily black Democratic electorates could deliver him a string of victories — though Mr. Sanders and Michael R. Bloomberg are fast on his heels in these states.

Mr. Bloomberg, who has invested more than half a billion dollars in ads nationwide, may face calls to exit the race if he fails to win at least one state today; his best chance appears to be in Virginia, but even there it’s far from a layup.

Elizabeth Warren has the resources to continue in the race, and her campaign is now banking on seizing the nomination at a contested convention — but she too is desperately hoping for her first win of the year. Her only clear opportunity comes in Massachusetts, her home state, though Mr. Sanders is doing his best to give her a run for her money there.

Below, read our rundown of the latest polling data from the six most delegate-rich states voting today.

The candidates still running in the Democratic primary are fanning out across the country on Super Tuesday as voters go to the polls. Here’s a look at where they plan to be throughout the day:

• Bernie Sanders is expected to head to his home state, Vermont, to cast his ballot and then hold a primary-night rally there in the evening.

• Joseph R. Biden Jr. plans to attend an event in Los Angeles in the early evening.

• Elizabeth Warren plans to spend the morning in Massachusetts, where she will vote, and then she will travel to Michigan to hold a primary-night event in Detroit.

• Michael R. Bloomberg is expected to spend his day campaigning in Florida — a state that is not holding its primaries until later this month. Mr. Bloomberg is scheduled to visit field offices in Miami and Orlando during the day and then go to an organizing event in West Palm Beach.

LOS ANGELES — Facing tough Super Tuesday prospects and skepticism that she has a path to the Democratic nomination, an energetic Elizabeth Warren took a swipe at Joe Biden on Monday night, after much of the Democratic establishment lined up behind him.

“No matter how many Washington insiders tell you to support him, nominating a fellow Washington insider will not meet this moment,” she told a crowd of thousands at East Los Angeles Community College. “Nominating a man who says we do not need any fundamental change in this country will not meet this moment.”

In front of a supportive crowd hours before 14 states were to begin voting, Ms. Warren tried to make the case that she was the best candidate for the party.

Read more Warren warns that nominating a candidate like Biden ‘is a big risk.’

“Nominating someone who wants to restore the world before Donald Trump, when the status quo has been leaving more and more people behind for decades, is a big risk for our party and our country,” she said.

Ms. Warren went on to give an extensive speech about the janitor strikes of the 1990s in Los Angeles, calling Latinas the “unsung heroes of the American story.”

“Latinas had led the fight and Latinas had won,” Ms. Warren said of the janitor strikes, which drastically increased the power of both unions and Latinos in Los Angeles. She drew parallels between the strikes and her campaign, adding: “It is not enough to have big ideas. It takes a plan to turn those ideas into reality.”

In providing a closing case before what is likely to be the most decisive day of the primary, she ended with what sounded like both an argument and a plea.

“We have this opportunity in 2020, this opportunity to come together to make real change,” she said. “This is our time. This is the moment we have been called to, the moment for us to make history.”

It’s going to be a big day, and a long one, with voting happening across time zones.

View more

To start with, here is when the polls close in 12 of the 14 states voting today. All times are in Eastern.

Read more Here’s when the polls close, and when you can expect results.

7 p.m.: Vermont, Virginia

7:30 p.m.: North Carolina

8 p.m.: Maine, Massachusetts, Oklahoma, Tennessee

8:30 p.m.: Arkansas

9 p.m.: Colorado, Minnesota

10 p.m.: Utah

11 p.m.: California

As for the other two states: The polls in parts of Alabama will close at 7, but most will not close until 8. And in Texas, most polls will close at 8, but in the far western part of the state, they will be open until 9.

The first definitive result of the night is likely to come in Vermont, Bernie Sanders’s home state, where we’re expecting the race to be called immediately after the polls close at 7. And we may get race calls in Alabama or Maine shortly after 8.

But the biggest prize of the night, California, tends to count slowly. Don’t expect delegate counts there tonight, or even tomorrow morning.

DALLAS — More than a year of contentious campaigning for president evaporated in a swift show of unity here on the eve of Super Tuesday, as both Amy Klobuchar and Beto O’Rourke shared the stage with Joseph R. Biden Jr. to offer their endorsement of the candidate.

“If you feel tired of the noise and the nonsense in our politics and if you are tired of the extremes, you have a home with me, and I think you know you have a home with Joe Biden,” Ms. Klobuchar said as she made her formal endorsement, bringing back familiar “Amy! Amy!” chants from the crowd. “Vote for decency, vote for dignity, vote for a heart for our country. That is what he will bring to the White House.”

Credit...Image by Erin Schaff/The New York Times

Read more Biden basks in endorsements from former rivals at a Dallas rally.

“Tomorrow, March 3, 2020, I will be casting my ballot for Joe Biden,” Mr. O’Rourke said after taking the stage to uproarious applause. “We need somebody who can beat Donald Trump.”

Mr. Biden spoke in between the two former presidential candidates, taking the stage after Ms. Klobuchar and before Mr. O’Rourke. He thanked Ms. Klobuchar — “You’re going to hear a lot from Amy Klobuchar,” he promised — before delivering a condensed version of his stump speech to a capacity crowd in downtown Dallas.

Mr. Biden, who romped to victory in South Carolina on Saturday, is now competing aggressively here in Texas and across the other delegate-rich states that vote on Tuesday, and has racked up a long list of endorsements since his win, including from Ms. Klobuchar and Pete Buttigieg on Monday alone. His path to victory in many of these states remains highly volatile and challenging — he has been vastly out-organized by two of his well-funded chief rivals, Bernie Sanders and Michael R. Bloomberg.

But his appearance here Monday night represented a remarkable turnaround from even a week ago, when after a fourth-place finish in Iowa, fifth-place showing in New Hampshire and second-place result in Nevada, his path forward looked uncertain.

He spoke against the backdrop of a giant Texas flag after receiving endorsements from Ms. Klobuchar and, earlier in the day, Mr. Buttigieg, who had appeared with him at a nearby restaurant.

“Folks, I wasn’t joking: Amy won all the debates,” Mr. Biden said.

After he finished, almost as a surprise, Mr. Biden welcomed Mr. O’Rourke onto the stage. The former Senate candidate in Texas, whose challenge to Senator Ted Cruz lifted him onto the national stage, pitched the former vice president as the ideal candidate to lead the ticket in Texas.

“Joe Biden is decent,” he said. “He’s kind. He’s caring. He’s empathetic.”

After he finished, Mr. Biden had a request of Mr. O’Rourke.

“You’re going to take care of the gun problem with me,” he said, as the crowd erupted again. “You’re going to be the one leading this effort.”

Joseph R. Biden Jr. is on the hottest streak of his campaign, after collecting endorsements on Monday from Amy Klobuchar, Pete Buttigieg and Beto O’Rourke. In addition to urging voters toward Mr. Biden, the three younger Democrats helped crystallize Mr. Biden’s appeal in their remarks about him, calling the former vice president a figure of unity and empathy, and a good bet for the general election.

Bernie Sanders is not yielding an inch, and from his elevated position in the race he has begun to make a blunter case against Mr. Biden, emphasizing his past support for unpopular trade deals and the 2003 invasion of Iraq. Mr. Biden has gotten something of a free pass from his opponents lately and that is now all but certain to change.

Two other prominent candidates, Elizabeth Warren and Michael R. Bloomberg, have continued to emphasize what they call their unique qualifications for the presidency. While they have serious ideological differences, they gave an overlapping critique of Mr. Biden and Mr. Sanders: that unlike themselves, those men, the leading centrist and progressive candidates, do not have an impressive record of actually getting things done.

Read more What to watch for on Super Tuesday.

We are most likely in for a long, long night. The biggest prizes will not be decided for days and perhaps weeks, when California hands out a huge trove of delegates. Mr. Sanders is hoping to win there by a wide enough margin to build a near-insurmountable lead that would put him hundreds of delegates ahead of Mr. Biden and the rest of the field.

We may get good signals about the trajectory of the race even from the states where polls close first — Eastern primaries in places like Virginia, North Carolina and Massachusetts.

If Mr. Sanders is on track to dominate the evening, it should be apparent from these states.

If we are headed for a surging Biden comeback, or a more muddled outcome, we may see evidence of that as well in these states.

We will also be watching to see if Ms. Warren prevails in her home state, Massachusetts, where Mr. Sanders campaigned last weekend. Ms. Warren has declined to call Massachusetts a must-win state for her candidacy, yet it is the only one she appears to have a good shot of carrying.

Mr. Bloomberg has spent a fortune — literally, a fortune — on a relatively short campaign, and he is competing hard in many Eastern and Southern states that Mr. Biden is also contesting. Whether Mr. Biden performs as strongly with black voters in those states as he did in South Carolina is a big test for his campaign.