Transcript for President Trump, Joe Biden face off in 1st presidential debate
And it is a big night in the race for the white house. The first presidential debate just a short time away. The high stakes showdown with 35 days now until the election and with early voting under way in parts of this country. President trump and Joe Biden about to face off for the first the president seen leaving the white house earlier today, he has arrived in Cleveland tonight. Joe Biden seen arriving in Cleveland on board a biden/harris plane. That will meet on this stage right here. There will be no handshake, no opening statements. And after a coin toss already, the president will get the first question and the president's team tonight expecting that question to be about that bombshell report about his and his reported debt, more than $400 million, much of it that may come due during his second term if he wins re-election. And, of course, the question now for many, who does the president owe that money to? Joe Biden countering today by releasing his own taxes. And after the president's repeated attacks on Biden's mental fitness, what Biden now says he expects from the president tonight. And how he plans to respond. And of course, this all plays out amid this pandemic. The toll on American jobs. The death of justice Ruth Bader Ginsburg and the president's new supreme court pick. And, of course, George Floyd, breonna Taylor and the conversation on race in this country. So, plenty to ask about tonight. Plenty to debate. And that will a short time from now. ABC's Mary Bruce leads us off from Cleveland. Reporter: Tonight, with the high stakes debate just hours away, president trump and Joe Biden touching down in Cleveland. The first question will go to the president and his team expects it to be on his taxes. Biden today already trying to seize the upper hand on the issue, releasing his latest tax returns, revealing he paid nearly $300,000 in federal taxes in 2019. We still don't know how much the president paid. It's under audit. They've been under audit for a long time. The irs does not treat me well. Reporter: But we do know what president trump paid in 2016, the year he won the white house. Just $750, according to "The new York Times." That same year, Biden paid more than 121 times that, $91,000. In debates four years ago with Hillary Clinton, she warned trump pays $0 in federal taxes. He paid zero. That means zero for troops, zero for vets, zero for schools. Reporter: But tonight, Biden walks out onto that debate stage armed with what the president did pay,$750, and in 11 out of 18 years, he paid nothing, according to "The time,". The president has long cast himself as a wildly successful businessman. Money money money Reporter: But in a new report today, "The times" says, quote, "It was all a hoax." Reporting when the show "The apprentice" debuted in 2004, he had almost $90 million in losses from his core businesses. And the times reports he owes debts of more than $421 million that could come due during a second trump term in the white house. Now the question, who does he owe that money to? Do you owe anybody money who is impacted by any decision you make as president of the United States? We need to know that. Reporter: Today, the Biden campaign with this blunt statement to trump -- "Mr. President, release your tax returns or shut up." The candidates are already taking shots. He's a dumb guy. Always known as a dumb guy. He doesn't know how to debate the facts. He's not that smart. Reporter: Biden is bracing for trump to go personal, telling supporters he won't take the bait. Biden telling David in that exclusive joint interview that he's ready for the president's attacks. I want to turn to the blistering attacks we've seen from president trump just this week alone on your mental fitness, whether you're up for the job. His campaign has called you diminished and I'm curious how you'd respond to that. Watch me. Mr. President, watch me. Reporter: This will be Biden's 27th debate for the white house. He's been doing it for 47 years and I've just started doing this stuff. Reporter: The president takes the stage down in the polls but is hoping his new pick for the supreme court will energize his base. Judge Amy coney Barrett today making her first visit to capitol hill. Trump is eager to get her confirmed by election day. She could be a deciding voice if the election results are contested. Biden is expected to hit on what's at stake with this supreme court pick, especially health care. With the court set to take up a case that could invalidate Obamacare the week after the election. Protections for pre-existing conditions for millions of Americans on the line. This is about people's health care in the middle of a pandemic. Reporter: And there's the virus. More than 200,000 Americans have died in this pandemic. For months, the president has been promising his own health care plan to replace Obamacare is coming. In the ABC news town hall, he was pressed -- where is it? I have it already, and it's a much better plan for you. Reporter: It still hasn't come. And for his part, Biden says there's only one thing he can do to counter the president tonight. What do you have to do to win the debate? Just tell the truth. So, let's get right to Mary, inside the debate hall right there in Cleveland tonight. And Mary, what are you hearing from the campaigns at this hour? We know the debate, just a short time from now. Reporter: Well, David, the president's campaign says he is done preparing and that he's feeling confident and in a good mood, while Biden's campaign says he is ready for anything. Now, because of the pandemic, tonight here, there will be no handshakes, no opening statements, just a limited socially distanced audience behind me. A debate like we have never seen before. David? Mary, thank you, all week long. I want to get right to Jonathan Karl tonight, Jon, so much at stake this evening. Joe Biden, of course, holding that lead nationally, but this could all come down to the key battleground states as we've seen so often. Let's look at our new poll out of Pennsylvania tonight. Among likely voters, Joe Biden now leads in Pennsylvania, 54% to the president's 45%. We've seen the polls shows a tight race, tied in Florida, a slight edge for Biden in other key battlegrounds from Michigan to Wisconsin, so, Jon, president trump clearly hoping to gain some ground tonight, Joe Biden with his poll numbers looking to avoid unforced errors? Reporter: David, by every single publicly available measure, Donald Trump is losing this race. As you mentioned, he has been trailing in the national polls for months. In all of the top 12 most hotly contested battleground states, he has not had a single consistent lead. Tonight is his best chance to change this and turn this around. I expect that he will try to do that by going ruthlessly on the attack against Joe Biden. Now, he's been doing that for months, nothing has really stuck. David, we may have two more debates to go, two more head-to-head debates between these two men, but people are already voting. If Donald Trump is going to change the dynamic in this race, he has to begin tonight. Point well made. Jon Karl at the debate site for us. Jon, thank you. And of course that crucial first debate just ahead here, ABC news with a special edition of "20/20" starting at 8:00 P.M. Eastern, followed by the debate at 9:00.
This transcript has been automatically generated and may not be 100% accurate.