 It's Morning Edition from NPR News. I'm Michelle Martin. And I'm Layla Faldin. Good morning. The current and former presidents of the United States debated last night for 90 minutes. And unlike the two times they met on stage in their last campaign, they did not interrupt each other. That's because the debate ground rules called for the mics to be muted. So for 90 minutes, Americans heard Joe Biden and Donald Trump in depth. On immigration, abortion, foreign policy, and the economy. Here is Biden. This is early in the CNN presidential debate.