He is trailing Democratic presidential nominee Joe Biden in most national and battleground state polls, making Thursday night's debate the incumbent's last best chance to change the trajectory of a race that, with less than two weeks to run, appears to favor the challenger.

After an initial match up that quickly descended into a glorified shouting match, with Trump repeatedly interrupting Biden and running roughshod over the moderator, the second debate, scheduled for last week, was canceled after the President tested positive for the coronavirus and subsequently refused to take part in a virtual meeting.

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This time, the Commission on Presidential Debates has given the green light to an in-person face-off, but with one unprecedented change: The candidates will have their microphones cut off while their opponents respond to the first question of each of the debate's six segments.

The topics slated for discussion over 90 uninterrupted minutes, beginning at 9 p.m. ET, include "Fighting COVID-19," "American Families," "Race in America," "Climate Change," "National Security" and "Leadership."

But that's just where the moderator, NBC's Kristen Welker, will begin. Where the candidates go from there, especially in Trump's case, is the wild card.

Here are five things to watch in the debate:

Will Trump trample over the new rules?

In order to enforce the debate's rule, the commission has resorted to something familiar to a country operating by video conferences: The mute button.

But there are questions over how effective the new guardrails will really be.

Trump's campaign has suggested that length of time will provide Biden with a chance to talk himself into a corner. True or not, past performance suggests Trump lacks the self-control to stand quietly by and find out. If he does try to interrupt, his voice could be picked up by Biden's microphone.

The President's sense of grievance over the changes could also lead him to lash out at Welker. His campaign has already attacked the commission and the President has a history of launching sexist attacks against female debate moderators.

Trump and his allies have been teeing up his plans to attack Welker and the commission by flouting the rules wherever they can. How Trump executes that strategy could provide the voters who haven't already cast a ballot with their last memory of the President before they make a decision.

Coronavirus on the rise

Trump wants to avoid the constant drumbeat of coronavirus news. Surging numbers across the country -- including swing states central to his victory -- make that impossible.

The national surge is significant: Johns Hopkins University found the United States reported over 60,000 new cases on Tuesday and 58,000 on Monday, leading public health experts to refer to this moment as a third surge in infections.

Politically, however, the numbers in swing states are even more dire. Both case and death numbers are on the rise in Wisconsin, Pennsylvania, Ohio, Iowa and Michiga