In the wake of Tuesday’s night’s brutally contentious presidential debate, Joe Biden’s campaign has released an ad online (below) that seizes on one of the most-discussed moments of the evening: when President Donald Trump declined to condemn white supremacists. When pressed by both debate moderator Chris Wallace and Biden to specifically condemn the violent, neo-fascist group dubbed the Proud Boys, Trump said “The Proud Boys? Stand back and stand by.”

“One known social media account for the group made ‘Stand back. Stand by’ part of its new logo,” NBC News reports. “On the Proud Boys’ account on the social media app Telegram, the group appeared to take the statement as marching orders. ‘Standing down and standing by sir,’ the account wrote.”

The Biden ad, released on Twitter this morning, excerpts Trump’s Proud Boys exchange from the debate followed by a black screen with the following text:

Comments from Proud Boys on online forums:
“This makes me so happy”
“We’re ready!”
“Standing by sir.”

In text accompanying the ad on Joe Biden’s official Twitter account, he writes, “There’s no other way to put it: the President of the United States refused to disavow white supremacists on the debate stage last night.”

Here’s the ad: