text:  This is CBS News on the Hour, sponsored by Progressive Insurance. I'm Jennifer Kuiper. They've been preparing for days, and now President Joe Biden and former President Donald Trump are set to face off in their first debate since October 2020. CBS's Nancy Cordes. I was speaking to a Biden aide a short time ago. He said that the president is in a good mood, he's well prepared, and he said something interesting. He said that President Biden is not going to shy away tonight from fact-checking Donald Trump.