 Learn more about smart business buying at AmazonBusiness.com. This is NPR. This is Morning Edition from NPR News. I'm E. Martinez in Culver City, California. And I'm Michelle Martin in Washington, D.C. It's said that any decision that reaches a president's desk is a hard one. The decision Joe Biden announced yesterday was one that only a handful of presidents before him have made. Biden is dropping out of the 2024 campaign, and he's endorsing his vice president, Kamala Harris.