Here’s what you need to know:
The first debate between Joseph R. Biden Jr. and President Trump, on Tuesday night in Cleveland, represents one of the president’s last, best chances to move a race that polls show him losing. But there are risks for Mr. Biden too.
Mr. Biden has lamented privately to advisers — and occasionally in public — that it was nearly impossible to debate during the Democratic primary season, when there were sometimes as many as a dozen candidates lined up on a single stage. Once the field narrowed, Mr. Biden told donors in Hollywood last fall, “You might actually get a chance to say something.”
Now, Mr. Biden will get his chance. Given his current edge in the polls, his advisers have