N.Y. Election: Voters Approve All 5 Ballot Measures

Mr. Trump had recorded a robocall urging voters to support Mr. Testa, and Mr. Testa had boasted of how the impeachment process had fired up the Republican base.

Within the Democratic Party, warfare is likely to continue as well.

Melinda Katz, the Queens borough president, easily defeated a Republican to become the next Queens district attorney. But while her victory on Tuesday was largely effortless, her path there was anything but: It involved the first boroughwide manual recount in recent memory, after the Democratic primary came down to a barely-there margin between Ms. Katz, who had the establishment’s blessing, and another candidate, Tiffany Cabán.

Ultimately, Ms. Cabán — a democratic socialist and former public defender who was endorsed by Representative Alexandria Ocasio-Cortez — lost to Ms. Katz by 55 votes.

A fight to shape criminal justice

Several other district attorney races also drew attention and boldfaced names, proof of growing attention by Democrats nationwide to prosecutor posts, which they see as a battleground ripe for progressive ideals.

In Monroe County in New York, which includes Rochester, Shani Curry Mitchell, a Democrat, challenged the Republican incumbent, Sandra Doorley, by running on a promise to curb mass incarceration, prioritize diversity and end “overcharging” of low-level offenders.

Ms. Mitchell attracted significant outside support: She was the beneficiary of more than $800,000 in outside spending by an activism group funded by the Democratic billionaire George Soros. But Ms. Doorley cast the spending as outsider interference, and she won by 12 percentage points with almost all precincts reporting.

In Ulster County, in the Hudson Valley, David Clegg, a Democrat, ran against Michael J. Kavanagh, a Republican backed by the Republican incumbent, who did not seek re-election. Mr. Soros also spent at least $184,000 supporting Mr. Clegg.