LOUISVILLE, Ky. — Voters endured 90-minute waits in Kentucky’s second-largest city, but the biggest hurdle facing election officials Tuesday seemed to be what wasn’t happening: quick counting of mail-in ballots for high-profile congressional primaries in that state and New York. Final results seemed unlikely for days.

In the day’s foremost contests, two young African American candidates with campaigns energized by nationwide protests for racial justice were challenging white Democratic establishment favorites for the party’s nominations.

First-term state legislator Charles Booker was hoping a late surge would carry him past former Marine fighter pilot Amy McGrath for the Democratic Senate nomination from Kentucky. And in New York, political newcomer Jamaal Bowman was seeking to derail House Foreign Affairs Committee Chairman Eliot Engel’s bid for a 17th term in Congress.

A deluge of mail-in ballots prompted by the coronavirus pandemic and slow-moving vote-counting procedures meant final results in those and other races would probably take days or more. That torturous wait seemed a preview of November, when numerous states will turn to mail-in voting like never before. Officials are already warning that uncertainty over who the next president will linger for days.

By late afternoon, there were scattered reports of long lines and absentee ballots that voters never received. Yet voting generally appeared smoother than in elections held in recent weeks in Georgia and Nevada, where some people stood in line for hours.

Waits lasting 90 minutes were reported Tuesday morning at the lone voting site in Lexington, Kentucky — Kroger Field, the University of Kentucky’s football stadium.

“This is definitely the longest that I’ve ever waited,” said 55-year-old Bob Woods, who stood with hundreds of others for over an hour to check in.

Voting was moving smoothly in Louisville, the state’s biggest city, where 600,000 residents also had only one polling place — the Kentucky Exposition Center.

“They should have more (elections) like this. You can get in and get out quick,” said 70-year-old Mary Moorman.

Voting advocates voiced concerns that unknown numbers of people stayed home because it was too difficult for them to travel to the sprawling fairground.

“In my neighborhood, most people don’t have cars,” said one voter, Michael Baker. “It’s not fair for them to have one site and it be so far away from people who are not able to commute here.”

New York state Attorney General Letitia James’ office received about 150 complaints by midafternoon, mainly about voters not getting absentee ballots they’d requested, polling sites opening late and voters receiving incomplete ballots.

Dena Cooper said she applied months ago for an absentee ballot that never arrived, so she went to her polling place in Brooklyn’s Bay Ridge to vote in person. She said a poll worker told her to go home and wait for the absentee ballot to arrive.

“I feel turned away,” Cooper said. In fact, New York voters who have requested but not used absentee ballots can legally vote in person. Cooper, a 32-year-old illustrator, planned to try again to vote Tuesday evening.