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Debatus interruptus, tracking the Biden-Trump debates

Artificial intelligence-assisted stress analysis of 2020 debates shows how often candidates felt in control

Signage for Thursday's presidential debate is seen as workers set up security fencing outside CNN's studios at the Turner Entertainment Networks in Atlanta.
Signage for Thursday's presidential debate is seen as workers set up security fencing outside CNN's studios at the Turner Entertainment Networks in Atlanta. (Andrew Harnik/Getty Images)

ANALYSIS — We don’t really know what to expect in this first debate of the 2024 general election between President Joe Biden and former President Donald Trump, but a look at the Roll Call data from their two 2020 debates suggests it will be one full of interruptions, diversions and the candidates generally feeling in control.

Their first debate, on Sept. 29, 2020, in Cleveland, was notoriously raucous. Moderator Chris Wallace did not seem in the mood to let any nonsense go unchallenged. Trump tended to expound on topics that did not always concern the question asked. And Biden frequently jabbed at Trump with short interjections. This contributed to, according to number crunching, each of the candidates getting out between 25-32 words before being interrupted, or once every, at most, 10.4 seconds.

Consider one very long 93-second stretch of that debate, starting at about 38 minutes and 46 seconds and ending at 40 minutes and 19 seconds, when Trump, Biden and Wallace spoke over each other or interrupted or interjected repeatedly, after a question about Trump’s taxes.

Trump: I paid millions of dollars in taxes, millions of dollars of income tax. And let me just tell you, there was a story in one of the papers that I paid

Biden: Show us your tax returns.

Trump: $38 million one year, I paid $27 million one year.

Biden: Show us your tax returns.

Trump: I went… You’ll see it as soon as it’s finished. You’ll see it. If you wanted to, go to the Board of Elections, there’s a 118-page or so report that says everything I have, every bank I have, I’m totally under leveraged because the assets are extremely good. And we have a very… I built a great company.

Wallace: Sir, I’m asking you a specific question, which is

Trump: Well let me tell you.

Wallace: I understand all of that. I’m asking you a question. Will you tell us how much you paid in federal income taxes in 2016 and 2017?

Trump: Millions of dollars.

Wallace: You paid millions of dollars?

Trump: Millions of dollars.

Wallace: So not 750?

Trump: Millions of dollars. And you’ll get to see it.

Biden: When?


Trump: But let me just tell you. Chris, let me tell you something, that it was the tax laws. I don’t want to pay tax. Before I came here, I was a private developer. I was a private business people. Like every other private person, unless they’re stupid, they go through the laws and that’s what it is. He passed a tax bill that gave us all these privileges for depreciation and for tax credits, we build the building and we get tax credits like the hotel on Pennsylvania Avenue.

Trump: You get a massive… Which by the way, was given to me by the Obama administration, if you can believe that. Now the men got fired right after that happened, but that’s a —

We could go on, but you get the picture, and even the transcript sometimes does not pick up every interjection, such as “Oh?” or “Phhhtt….” We have it all at Roll Call, with supplementary tools to analyze them.

The upshot? Biden and Trump gave little quarter to one another, and Wallace pressed on follow-ups.

Of note, though, and despite the debate’s reputation for skidding against the guardrails, the two candidates felt relatively under control. According to a filter of the transcript and video through the Roll Call StressLens analysis, there were only 98 total seconds out of the 94-minute, 15-second debate when Biden or Trump did not feel like they had control of the situation. That analysis takes into account the standard deviation from their normal voice patterns. (For more on that, see our methodology note below.)

Regardless of how one feels about the utility of this debate and how it played out, it led to some changes in format for the second one, on Oct. 22, 2020, in Nashville. The candidates’ microphones were muted for the first two minutes when it was their opponent’s turn to speak. The moderator, Kristin Welker, kept a tighter ship.

This time, Trump and Biden were able to get in anywhere from 66-88 words and 22-29 seconds between interruptions.

Interestingly, their stress levels went up. Over the course of the 99-minute, 34-second debate, Trump and Biden combined did not feel in control of the situation for eight minutes and 52 seconds, according to the StressLens analysis.

Thursday’s debate in Atlanta might tend toward the Nashville one, with rules muting microphones when it is the opponent’s turn to speak and no studio audience, nor opening statements from either candidate. You can follow along with our live analysis of the Atlanta debate at

Methodology note: The Roll Call StressLens analysis of the 2020 debates is based on more than 2000 hours each of audio and video of Biden and Trump in multiple other settings, which enables detection of deviations associated with their individual physiological voice patterns. Over one standard deviation is evidence of a lack of perceived control by the speaker.