Trump has made several comments about going after his political opponents and retribution. Asked to clarify what he meant, Trump replied, "Well, I said my retribution is going to be success."

He also contended that he's done nothing wrong despite his numerous criminal and civil cases.

Biden fired back contending that Trump's claims that he has the right to seek retribution is wrong. He then went after Trump over his various scandals.

"The crimes you are still charged with and think of all the civil penalties you have, how many billions of dollars ... and civil penalties? For molesting a woman in public for doing a whole range of things ... having sex with a porn star ... while your wife was pregnant? What would you be talking about? You have the morals of an alley cat," Biden said.

After a stifled and stumbling opening statement, Biden has had some good replies to Trump when talking about policy -- especially on abortion and Jan. 6. But that will be little comfort for his campaign, which is fighting hard against the impression that Biden is too old to hold office. In a 538/Ipsos poll of Americans released today, 40% of Americans said they rated Biden's mental fitness to be president as "terrible," compared to 35% for Trump -- and fewer Americans rate him positively for his physical fitness to lead, too.

538's election forecasting model currently gives Biden and Trump each a 50-in-100 chance of winning the election. Biden's initial impression could prevent him from making sizable gains over those numbers, despite the rest of his performance.

-538's G. Elliott Morris

When asked point-blank whether he believes the millions of Americans who are likely to vote for Trump will be voting against American democracy -- in reference to the president's past comment that Trump and his MAGA Republicans are "determined to destroy American democracy," Biden responded, "Yes, the more they know about what he's done."

Biden went on to reference Trump's comment that there were "very fine people on both sides" of clashes at a white supremacist rally in Charlottesville, Virginia, in 2017.

"This guy has no sense of American democracy," Biden said.

Trump called his accusation false.

False. During an exchange on the attack on the Capitol on Jan. 6, Trump pivoted to the quick action he says he took to stop rioting in Minneapolis after George Floyd was killed in the custody of a Minneapolis police officer.

"If I didn’t bring in the National Guard, that city would have been destroyed," Trump claimed.

It was Gov. Tim Walz who activated 500 Minnesota National Guardsmen to provide support to local law enforcement in Minneapolis.

-Analysis by Aaron Sharockman, PolitiFact

Heading into tonight's event, Biden and Trump are locked in a close contest. 538's presidential election forecast rates the race as a dead heat, with both Biden and Trump having about a 1 in 2 shot of winning the election. This falls in line with our national polling average, which has the two candidates just about tied at 41%, with Kennedy polling at 9%.

But as readers know, U.S. presidential elections aren't decided by the national popular vote. Instead, they're decided by the Electoral College, where the results in individual states determine who wins each state's electoral votes, with a majority of 270 out of 538 in total necessary to claim victory. Currently, the forecast shows an extremely tight race in each of the most pivotal states.

For instance, Biden's path to victory may rest primarily on winning the Frost Belt battlegrounds of Michigan, Pennsylvania and Wisconsin that he carried in 2020. While the forecast shows him with small leads in each of those states, Biden's advantage is well inside the range of potential outcomes, meaning Trump could easily carry them once we get to November. Meanwhile, Trump holds a narrow edge in the Sun Belt swing states of Arizona, Georgia, Nevada and North Carolina, but similarly his leads are far from secure.

Still, with nearly four months to go until Election Day, there's a great deal of uncertainty around where public opinion will stand when voters cast their ballots. 538's forecast utilizes a combination of polling information and campaign fundamentals, such as the economic situation and each state's partisan leanings. Together, those indicators show a toss-up race that could go in either direction.

Now, tonight's debate could move the contest: Historically, the margin in presidential races has shifted by an average of about 2 points in the two weeks following the first general election debate in cycles dating back to 1976. In what could be bad news for Biden, that movement has more often than not gone against the incumbent president or party. Yet we're still sailing in uncharted waters. After all, this election involves both a sitting and former president, an unprecedented matchup in modern times. The debate is history-making, too: It's nearly three months earlier than any past general election face-off.

-538's Geoffrey Skelley