Opinion | The Court Mitch McConnell Built

Mitch McConnell openly celebrated the Supreme Court’s landmark 5-to-4 ruling on Thursday that declared the court had no power to interfere in excessively partisan gerrymandering. He had earned his victory lap. After all, Mr. McConnell, the Kentucky Republican and Senate majority leader, created the current court to deliver precisely that sort of outcome.

His audacious decision in February 2016 to prevent President Barack Obama from filling the vacancy caused by the death of Justice Antonin Scalia contributed significantly to the election of Donald Trump as president, allowing Mr. McConnell to oversee the Senate confirmations of Justices Neil M. Gorsuch and Brett M. Kavanaugh.

They were, predictably, two of the five justices in the conservative majority that refused to rein in wildly partisan redistricting, despite acknowledging that such tactics threaten to subvert democracy. Under the Constitution, policing gerrymandering is the job of the political system, not the judicial one, the five Republican-nominated justices said.

“This is a good example of how a strict constructionist would look at an issue,” Mr. McConnell said about the ruling, which will clearly benefit the Republicans who control most of the state legislatures that will draw political maps using the 2020 census. “The founding fathers of this country were not ambiguous about who would do redistricting.”

A Supreme Court that included Merrick B. Garland, the chief judge of the United States Court of Appeals for the District of Columbia Circuit — Mr. Obama’s 2016 nominee — very likely would have decided the districting case very differently.

You can bet that this will not be the last end-of-term 5-to-4 vote in a politically charged Supreme Court decision. The justices like to say they don’t wear party identification on their robes. But the party label of the president who made the nomination is becoming a dependable indicator of how a Supreme Court justice will rule. And that is particularly clear in the major cases arising out of the political and cultural divisions of the moment.

“Today’s partisan split is anything but a flash in the pan,” the legal scholars Neal Devins and Lawrence Baum wrote in their book, “The Company They Keep,” arguing that the justices are heavily influenced not only by who appoints them, but also their own elite social networks. “It now defines the court and will likely play a key role in court decision making for the foreseeable future.”

At the moment, there appears to be one wild card preventing the court from tipping over into all-out partisanship: Chief Justice John G. Roberts Jr., who abhors talk of the court as a political body.

“People need to know that we are not doing politics,” he said in a speech earlier this year at Belmont University College of Law in Nashville. “They need to know that we’re doing something different, that we’re applying the law.”

In previously navigating a way to uphold the Affordable Care Act, Chief Justice Roberts had given every indication that he was worried about the court’s image.

He acted similarly last week in joining the four justices nominated by Democrats in writing an opinion that sent back to a lower court a politically inflammatory case about whether to add a question about citizenship to the coming census. The question is viewed as a backdoor effort by the Trump administration to undercount minorities and dilute their political influence.

Chief Justice Roberts seemed to recognize that allowing the court to deliver two major political victories for Republicans would have fueled increasing Democratic mistrust of the Supreme Court. But in trying to maintain the court’s reputation — however tarnished — of judicial nonpartisanship, he underscored just how political the court has become.

The chief justice’s efforts to steer the court through partisan shoals is likely to get even more difficult as the justices are called upon to referee hot-button issues left unaddressed by partisan dysfunction in Congress and the White House.

Complicating his task is the fact that the other four conservatives — Justices Gorsuch, Kavanaugh, Clarence Thomas and Samuel A. Alito Jr. — seem to be forming a power center not easily influenced by the chief justice. If President Trump were able to replace one of the remaining liberals on the court, it would fortify a conservative majority that would not need the chief justice’s vote. And Democrats, with the changes in nomination rules imposed by both parties over the past six years, would have no power to stop it.

All of this makes this moment seem particularly perilous for the court. Though it has long been held in higher esteem than the other two branches, a growing number of Americans see it as infected by partisanship — and are questioning its legitimacy. In the eyes of many, Democrats in particular, the stonewalling of Judge Garland that led to Justice Gorsuch’s nomination and the accusations of sexual misconduct against Justice Kavanaugh have tainted both men’s confirmations.

As has long been noted, the Supreme Court has no army to enforce its rulings. Its legal — and moral — authority stems almost entirely from the willingness of Congress, the president and the American public to accept its decisions. What might happen if that authority dissipates?

If, for instance, the court overturns a major precedent — say, the Roe v. Wade decision legalizing abortion — or is seen as relentlessly working to consolidate Republican political power, Democrats in Congress will feel increasing pressure to act. Some Democratic presidential candidates have already proposed plans for restructuring the court.

One widely discussed idea would be to abolish lifetime tenure and establish term limits for justices, to dilute the influence of any individual president. Pete Buttigieg, one of those Democratic candidates, has proposed creating a 15-member court with five members chosen by Republicans, five by the Democrats and five chosen by the other 10. Some Democrats have called for expanding the number of seats on the court to offset the conservative bloc. And yet another idea, seemingly embraced by Senator Bernie Sanders during the Democratic presidential debate, would establish a rotating corps of justices.

“I do not believe in packing the court,” Mr. Sanders said. “But I do believe that constitutionally we have the power to rotate judges to other courts. And that brings in new blood into the Supreme Court.”

But none of these ideas, of course, stand a chance unless the Democrats capture the White House and both houses of Congress, since Republicans are happy with the court as it is.

Mr. McConnell did offer one concession. If a Democrat wins the White House in 2020 and Republicans still control the Senate, he will consider bringing a Supreme Court nominee before the Senate if a vacancy occurs early in the new president’s term.

“I can’t imagine any scenario under which in the early part of any president’s term you would not have a vote,” Mr. McConnell said. Then he offered an important caveat. A vote, he said, “doesn’t mean the person will necessarily be confirmed.”

Mr. McConnell will not easily relinquish control over the court he was so instrumental in shaping.