President Joe Biden and former President Donald Trump will face off in a historic debate Thursday on CNN.

It's the first debate between a sitting president and a former president. It will also be the first debate since 2020 featuring either Biden, who did not face a serious challenge for the Democratic nomination, or Trump, the presumptive Republican nominee who skipped all the GOP debates during primary season.

The last time they met on the same debate stage was in Nashville, Tennessee, on October 22, 2020. Because their first debate quickly descended into a glorified shouting match, the Commission on Presidential Debates instituted an unprecedented change: The candidates had their microphones cut off while their opponent responded to the first question of each of the debate's six segments.

Workers prepare the debate stage the day before the event. There was <a href="index.php?page=&url=https%3A%2F%2Fwww.cnn.com%2Fpolitics%2Flive-news%2Fpresidential-debate-coverage-fact-check-10-22-20%2Fh_b688ad875a34437c2e2ab8d13e80a468" target="_blank">a last-minute agreement</a> to remove plexiglass barriers that would've been placed between the candidates.
Workers prepare the debate stage the day before the event. There was a last-minute agreement to remove plexiglass barriers that would've been placed between the candidates.
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First lady Melania Trump attends the debate.
First lady Melania Trump attends the debate.
Jim Watson/AFP/Getty Images
Biden's wife, Jill, second from left, walks by some of Trump's children as they attend the debate.
Biden's wife, Jill, second from left, walks by some of Trump's children as they attend the debate.
Brenden Smialowski/AFP/Getty Images
The stage is set ahead of the debate.
The stage is set ahead of the debate.
Eric Baradat/AFP/Getty Images
Professional golfer John Daly, left, and musician Kid Rock take their seats at the debate site. Both were supporting Trump.
Professional golfer John Daly, left, and musician Kid Rock take their seats at the debate site. Both were supporting Trump.
Brendan Smialowski/AFP/Getty Images
Biden and Trump arrive on stage at the start of the debate.
Biden and Trump arrive on stage at the start of the debate.
Jim Bourg/Reuters
Biden answers a question during the debate. At the time, Biden had a larger lead in national polls than Hillary Clinton did at this same point in 2016. <a href="index.php?page=&url=https%3A%2F%2Fwww.cnn.com%2Felection%2F2020%2Fpresidential-polls" target="_blank">In CNN's Poll of Polls,</a> Biden led Trump by 10 points nationally and was also showing considerable strength in the key battleground states of Pennsylvania, Michigan and Wisconsin where Trump won by narrow margins in 2016.
Biden answers a question during the debate. At the time, Biden had a larger lead in national polls than Hillary Clinton did at this same point in 2016. In CNN's Poll of Polls, Biden led Trump by 10 points nationally and was also showing considerable strength in the key battleground states of Pennsylvania, Michigan and Wisconsin where Trump won by narrow margins in 2016.
Julio Cortez/AP
People watch the debate from their vehicles in San Francisco.
People watch the debate from their vehicles in San Francisco.
Jeff Chiu/AP
Trump spoke about his own experience fighting Covid-19 and downplayed a spike, which medical experts had been warning about for months as the country headed into the fall and winter. "There are some spikes and surges in other places. They will soon be gone," Trump said.
Trump spoke about his own experience fighting Covid-19 and downplayed a spike, which medical experts had been warning about for months as the country headed into the fall and winter. "There are some spikes and surges in other places. They will soon be gone," Trump said.
Jim Bourg/Pool/AP
Biden holds up a mask as Trump takes notes during the debate section about Covid-19.
Biden holds up a mask as Trump takes notes during the debate section about Covid-19.
Morry Gash/Pool/AP
The debate took place on the campus of Belmont University in Nashville.
The debate took place on the campus of Belmont University in Nashville.
Brendan Smialowski/AFP/Getty Images
The two men offered sharply different visions for the months ahead. At the time, Covid-19 cases were rising in more than 30 states.
The two men offered sharply different visions for the months ahead. At the time, Covid-19 cases were rising in more than 30 states.
Morry Gash/Pool/AFP/Getty Images
The debate was far more substantive and controlled than their first presidential debate, which turned into a glorified shouting match.
The debate was far more substantive and controlled than their first presidential debate, which turned into a glorified shouting match.
Jonathan Ernst/Reuters
A timer is shown near Trump. Each candidate got two uninterrupted minutes to speak at the start of each debate segment.
A timer is shown near Trump. Each candidate got two uninterrupted minutes to speak at the start of each debate segment.
Jim Bourg/Pool/Getty Images
Biden looks at his watch during the debate. It lasted a little over 90 minutes.
Biden looks at his watch during the debate. It lasted a little over 90 minutes.
Brendan Smialowski/AFP/Getty Images
The lecterns were separated by more than 12 feet.
The lecterns were separated by more than 12 feet.
Chip Somodevilla/Getty Images
Welker asks a question.
Welker asks a question.
Morry Gash/Pool/Getty Images)
Trump and Biden are joined by their spouses at the end of the debate.
Trump and Biden are joined by their spouses at the end of the debate.
Jim Watson/AFP/Getty Images
People watch demonstrations taking place at Belmont University before the debate.
People watch demonstrations taking place at Belmont University before the debate.
Mark Humphrey/AP