6 things to look for in the first Biden-Trump presidential debate - CNN

And top Democratic operatives believe Biden will use the revelation to attack the President during the debate.

The story is a gift for Biden, whose campaign has been running on populist rhetoric that casts Trump as out of touch with average Americans.

That tactic will be challenged on Tuesday.

Biden's low bar

Trump and his campaign spent months and millions of advertising dollars casting Biden as senile -- seizing on every verbal stumble, often with misleading or out-of-context videos -- in an effort to plant doubt in voters' minds that the 77-year-old former vice president is up for the job, while falsely suggesting that Biden was trying to duck the debates.

Seemingly late to grasp the likelihood that setting such low expectations for Biden could backfire, the President in recent days pivoted to a new, baseless theory on Twitter to explain away a potentially strong Biden performance -- one Trump used without evidence against Hillary Clinton in 2016, too: that Biden will take performance-enhancing drugs.

And in the eyes of the older, independent and suburban voters who polls show have shifted away from Trump since 2016, Biden could benefit from the low bar the President has set by merely holding his own.

Not only has it forced both campaigns to rethink the way they operate, Trump's handling of Covid-19 has become the dominant issue for Biden.

And Tuesday represents a chance for the former vice president to take those critiques directly to the President.

Biden aides believe that the pandemic is the reason the election polling has remained steady, and the former vice president looks poised to make it a central part of his attack on Tuesday.

Trump repeatedly tells the same story on the virus: He blames China, talks up the increases in testing in the United States and then touts the possibility that a vaccine could be approved soon.

All of those points have significant holes in them for Biden to exploit, and Trump proved at an ABC News town hall earlier this month that he struggles to answer direct questions about the virus when he leaves the confines of Fox News and other friendly conservative outlets.

Trump's Supreme Court momentum

Republicans' decision to press forward with a Supreme Court confirmation just weeks before the presidential election -- ignoring the principle they created four years earlier, when they refused to consider then-President Barack Obama's nominee nine months before the election -- is all but certain to be a flashpoint Tuesday night.

Fahrenkopf Jr., co-chair of the Commission on Presidential Debates, told CNN on Sunday that they don't "expect" any of the moderators to fact-check Trump or Biden in the moment.

"The minute the TV is off there will be plenty of fact checkers," said Fahrenkopf.

And a Biden aide with knowledge of the debate process told CNN that the former vice president doesn't intend to fact-check Trump's falsehoods, even if the President routinely pivots to them.

won't be to try to fact-check him in real time or to let lies and absurdities go in the hope that moderators -- or viewers -- catch them," wrote Philippe Reines, a former aide to Hillary Clinton who played Trump during her 2016 debate prep.

Instead, wrote Reines, Biden should preempt the President early in the debate by noting that he frequently tells lies.

A pivotal section on race

The section on race pits each candidate's core arguments against the other's.