Lots of drama but little certainty in the Kentucky and New York primaries

One after another, left-wing challengers faced New York headlines, including Representative Gregory Meeks, chairman of the Queens Democratic Party; Representative Yvette Clarke, who faced a number of upstart candidates in Brooklyn; and Representative Carolyn Maloney, who represents parts of three boroughs of New York City.

Jerrold Nadler, the chair of the high-profile House Judiciary Committee, and Ms. Ocasio-Cortez also faced challenges.

While Democrats dominate in New York, two traditionally Republican seats were also drawing interest from either end of the state: on Long Island, Representative Peter King, the most prominent Republican member of Congress, retires, leaving an open race, and Los Democrats dream of a November pickup.

And in western New York, Nate McMurray, a Democrat, was looking to flip the bright red 27th congressional district, most recently retained by Rep. Chris Collins, who resigned last fall just before pleading guilty to federal charges of insider trading. His opponent, State Senator Chris Jacobs, was favored to win in a district that voted overwhelmingly for President Trump, although some Republicans seemed suspicious, and both Mr. Trump and his son offered endorsements for Mr. Jacobs in the closing days of the Bell.

Two House seats, filled by retired Democrats in the Lower Hudson Valley and the Bronx, were also closely watched with a list of candidates in both districts.

At In the Hudson Valley district, held by Representative Nita Lowey, seven Democrats were on the run, including Mondaire Jones, a Harvard-educated attorney seeking to become the first openly gay black member of Congress; David Carlucci, a state senator who had worked closely with Republicans in Albany; and Adam Schleifer, a former prosecutor and the son of a billionaire pharmaceutical executive.

Further south in the Bronx’s 15th Congressional District, an even bigger wrestling was underway, with a collection of rising Democratic stars and older political veterans seeking to replace outgoing Congressman José E. Serrano. There, the favorite appeared to Rubén Díaz Sr., a former conservative state senator with a history of anti-gay comments. But if city councilman Ritchie Torres were victorious, he, too, could be the first openly gay black member of Congress.

Across the state, the global pandemic changed the practicalities of electoral democracy: in late April, after the deaths of thousands of New Yorkers, and amid fears of a second wave, Governor Andrew M. Cuomo increased the access to absentee voting by mail, resulting in election officials issuing nearly two million ballots to voters statewide. Mr. Cuomo then allowed those ballots to be killed until Election Day.

The sheer number of absent ballots to be counted could be daunting for election officials who anticipate that polling stations were remade in the coronavirus era, including workers in masks enforcing the six-foot social distance rules and cleaning the ballot scanners with disinfectant. Concerns about the large number of absentee ballots were especially acute given the intense and hectic battles over vote counts even before the coronavirus, such as last year’s disputed election for the district attorney in Queens.