Get ready for a long election night — or nights. Don't expect to know the winner right away from Tuesday's presidential contest between Vice President Kamala Harris, a Democrat, and former President Donald Trump, a Republican. For the second straight presidential election, there probably will be no clear winner immediately and early returns could give a false impression. Several reasons explain this likelihood:

• Polls suggest the race is very close. Recounts are possible in some areas.
• It takes extra time to physically count millions of paper ballots that were mailed.
• California and New York allow mail ballots to be received up to seven days after the election. Nevada counts mail votes postmarked by Election Day if received up to four days later.

"A slower count has nothing to do with accuracy or legitimacy of the process," says Joyce Vance, a former federal prosecutor who's now a Substack blogger and MSNBC commentator. "A slow count means a careful, accurate count. . . . Getting it right is more important than getting it fast." She posted last week that "many 'results' on Election Night are media projections based on exit polling. That type of educated prediction is much more difficult when significant numbers of people vote by mail." Another prominent expert, election lawyer Benjamin Ginsberg, wrote last week in The New York Times: "Delays themselves are not evidence of a conspiracy. They should not breed mistrust." He's a political analyst for MSNBC and a former attorney for Republican campaigns.

In 2020, the race between Joseph Biden and Trump was called for the Democrat on following Saturday -- four days after polls shut. Seven decisive states — Arizona, Georgia, Michigan, Nevada, North Carolina, Pennsylvania and Wisconsin — remained uncalled the next morning. (The same states are seen as pivotal again.) The nation watched results trickle in slowly for three days before more states were called.

Even after all counting, the result could be challenged by lawsuits and court battles, as Trump tried in 2020. The ex-president, who faces federal criminal charges over his efforts to overturn his 2020 defeat, doesn't pledged to accept this year's results. He accuses the opposing party, without evidence, of undercutting election fairness and claims the only way he can lose is if Democrats cheat. Republican lawyers and activist groups, along with the Republican National Committee, are prepared to challenge how results are officially certified by Congress in the weeks before that happens on Jan. 6, 2025. "This could be the most consequential month in modern American history," writes New York Times columnist Bret Stephens.

State official says: "Candidates don’t get to decide who wins elections, voters do. . . . Officials will be working to transmit results as quickly and efficiently as possible." -- Jocelyn Benson, the Democratic secretary of state in Michigan

Columnist says: "The scenario that worries me most is a really narrow victory by one side or the other, which leads to multiple recounts in one or more states, along with weeks of legal uncertainty. At that point, we're staring into the abyss." – Bret Stephens, The New York Times

Media's role: "The media plays a significant role in either mitigating or exacerbating tensions around elections. . . . This means not only getting the facts right but also considering how headlines and stories can influence public perception and behavior." – Tina Barton, Committee for Safe and Secure Elections, a bipartisan group