NEW: Late night host Jimmy Fallon trolls Biden for being a mumbling mess during his debate announcement, says Biden wants the debate on CNN because they have no audience. “One of Biden's debate conditions was not having an audience… So that explains why it's on CNN.” “Another condition from Biden is that he wants microphones that automatically cut off when a candidate hits their time limit.” “Biden got the idea after his last press conference when his staff was like: ‘We need a microphone that automatically cuts off.’”