 There is a lot of polling data out there now that does suggest that Biden is still a viable candidate, but just not as viable as someone else. There's so much polling that shows so many Americans don't actually like Donald Trump that if Democrats replaced Biden, they would probably have an easier time beating Trump. In the same way, if Republicans replaced Trump with someone else, they'd have an easier time beating Biden. But right now we're locked in. Trump versus Biden. And Biden last night made it much harder for the Democrats to get him out of the race, even though they're trying.