How the CNN mute button will work at tonight's Biden-Trump debate

CNN on Thursday night will beusing a mute button that can cut off President Biden and former President Trump during the first presidential debate, in a bid by the network to avoid a repeat of the raucous clash between the two in 2020.

During the 2020 debate, Biden and Trump repeatedly talked over and insulted one another. The animosity between the two candidates, and the importance of Thursday night's battle, increases the odds that both men will be aggressive on the Atlanta stage.

The mute botton is intended to help viewers understand the candidates, but it also carries risks for CNN.

Trump's campaign ahead of the debate has already put forward the argument that the moderators, CNN anchors Jake Tapper and Dana Bash, will treat their candidate disfavorably.

CNN says its debate night control room will mute the microphones of candidates when it is not their turn to speak.

But Tapper and Bash will also be "empowered to use all tools at their disposal to enforce timing and ensure a civilized discussion.” 

The network previewed how the debate will look and sound during a segment on Wednesday evening.

"Candidates will have two minutes to answer questions and one minute for responses and rebuttals. At the moderators’ discretion, there may be an additional minute for follow-ups, clarifications, or responses," anchor Phil Mattingly said during the segment, which aired in prime time and was first highlighted by Mediate.

Attached to the cameras in the studio and in the candidates field of view are the timing lights, Mattingly said.

"When the lights show yellow, there are 15 seconds left in the candidate’s answer or response. When the lights flash red, there are five seconds left, and when the display is solid red, the time is up," he explained. "At that point, the candidate’s microphone will be turned off and the other candidate will have their microphone turned on."

CNN anchor Victor Blackwell, during the same explanatory segment, showed viewers how lights on each podium will be lit up green when it is their turn to speak.

CNN’s production team shared the demonstration with both campaigns on Wednesday, and Mattingly noted "by agreeing to participate in this debate, both campaigns and candidates have also agreed to abide by these rules."

The 90-minute debate will include two commercial breaks, and campaign staff cannot interact with their candidate during the break, the network said.

Thursday night's will be the first of two scheduled debates between the presidential election this fall, the second slated for September on ABC.