Politico reports:
The mythology of presidential debates is all about fateful moments — clever lines or terrible blunders or cutting exchanges that unfold in seconds but live in memory for decades.
The best examples still echo: Ronald Reagan stealing the show in a Republican primary debate in 1980 by saying he paid for that microphone, Lloyd Bentsen in 1988 telling Dan Quayle that he is no Jack Kennedy, George H.W. Bush in 1992 looking impatiently at his watch.
The PBS NewsHour/POLITICO Democratic debate on Thursday night will be the sixth encounter of the nominating contest. Looking back at the first five debates, the viral moments they produced proved ephemeral, the political equivalent of a 24-hour flu.
Start time is 8PM Eastern.