Thinking more on the debate. Biden screwed up because he, like most on the left, never bothered to understand Trump. Some would say Trump's interruptions were "rude", fair enough but many were also funny. Trump used sarcasm to get his point across. Biden didn't. He just used

... nastiness. He was petty, vindictive, rude and out of control. Trump interrupted to make a point or push back on Biden's talking points. Biden( and Chris to some degree) just interrupted to shut Trump up. In the same way the left can't meme, they can't use sarcasm to effect.

Both require humor. Biden showed he had none and simply came across as an old guy yelling at Trump to get the hell off his yard. It was a very bad look for Biden. If Trump came across as half as vindictive and nasty as Biden did tonight, he would never have been elected.