The bar to improve upon their last meeting is low: Their first debate was punctuated by frequent interruptions, mostly from Mr Trump, leaving the two men talking over each other and Mr Biden eventually telling the president to “shut up”.
A planned second debate did not happen after the president was diagnosed with coronavirus and refused to participate in a virtual format. Mr Biden and Mr Trump instead participated in town hall events on competing television networks.
The new debate, taking place in Nashville, Tennessee, marks the candidates’ second and final face-to-face meeting, with election day less than two weeks away.
Here’s what to look out for:
– Muted microphones
After viewers of the last presidential debate bemoaned the moderator’s inability to cut off the candidates’ microphones, the non-partisan Commission on Presidential Debates responded with an announcement this week that each candidate’s microphone will be turned off while his opponent gives a two-minute answer to an initial question on each debate topic.
After those initial replies, the microphones will stay on during open discussion, leaving it likely there will still be lots of crosstalk during rebuttals.
Since the last debate, Mr Trump was diagnosed with Covid-19. The Republican has cast the virus and his own infection in positive terms, resumed holding large campaign rallies and attacked the government’s top infectious disease expert, Dr Anthony Fauci.
Mr Biden, who has portrayed the Trump administration’s response as an abject failure, has taken a much more cautious approach. He regularly wears a mask, holds small in-person campaign events and releases his Covid-19 test results, which so far have been negative.
– Family and personal attacks
The president for months has been making accusations of corruption against Mr Biden and has lately intensified his focus on unverified claims about Mr Biden’s son Hunter. During the last debate, the president did not shy away from bringing up Mr Biden’s family, and attacked Mr Biden’s intelligence.
Biden aides anticipate Mr Trump will again level searing personal attacks during the debate. The Democrat is expected to try to redirect to his core argument that Mr Trump is unfit for the job.
Following a summer marked by protests across the country over racial injustice, Mr Trump has repeatedly portrayed himself as a greater champion for black Americans than Mr Biden, while emphasising a law-and-order theme. But during the last debate, Mr Trump gave a reluctant answer when asked if he would condemn white supremacists, and he refused to outright condemn a far-right fascist group, instead telling them to “stand back and stand by”.
Mr Biden, who frequently acknowledges systemic racism, has accused the president of encouraging a rise of white supremacy and armed militias and cites Mr Trump’s comments that there were “good people” on both sides of a 2017 white supremacist rally in Charlottesville, Virginia, as the impetus for his presidential run.
– Leadership and national security
Mr Trump is expected to continue promoting his “America First” policies, which have pulled the US out of multilateral agreements that he maintains were not in the country’s interests. He is also likely to highlight construction of more than 200 miles of his promised wall along the US-Mexico border and recently brokered deals normalising relations between Bahrain and the United Arab Emirates and Israel.
Mr Biden has accused the president of alienating long-standing US allies. He is expected to focus on Mr Trump’s efforts to sustain a relationship with Vladimir Putin’s Russia despite warnings from US intelligence agencies that Russia interfered in the 2016 US presidential election.
Immigration is not among the featured topics expected during the debate, but Mr Biden may seek to raise the issue on the heels of a report this week that court-appointed lawyers have been unable to find the parents of 545 children separated at the US-Mexico border early in the Trump administration.
Mr Biden has repeatedly criticised Mr Trump’s immigration policies, something that Mr Trump featured prominently in his 2016 campaign.
– Moderator and format
The debate will be moderated by NBC News White House correspondent Kristen Welker. She will be the first black woman to serve as the moderator of a presidential debate since Carole Simpson in 1992.
The debate will be divided into six 15-minute segments, each on a topic selected by Ms Welker: Fighting Covid-19, American families, race in America, climate change, national security and leadership.