Joe Biden leads Donald Trump in Pennsylvania and Florida, according to new Times/Siena polls taken after the first debate.
Biden leads in Pennsylvania, 49 to 42 percent among likely voters. He leads in Florida, 47 to 42. https://www.nytimes.com/2020/10/03/upshot/polls-election-florida-pennsylvania.html

In an analysis of interviews conducted yesterday, including in Arizona (where a poll is ongoing), there was modest evidence of a shift in Joe Biden's direction after Trump's COVID diagnosis. That said, one day of interviews is not nearly enough to reach any firm conclusions

The shift, though, would be material if confirmed and it was statistically significant, controlling for the demographic and political variables used in weighting. That said, it's still just one day of interviews. We'll have to wait and see here.

Of the two results, the biggest surprise was probably Florida, where we found Biden+5 with a R+4 sample. This is a fully updated voter file that reflects some meaningful GOP registration gains in the states.

It's just a subsample, so big MoEs here, but we found no evidence of the big Trump gains among Hispanic voters in Florida or in Miami-Dade County. Biden even narrowly led a (very small) sample of Cuban voters; they were R 47-28 by registration. Again, small samples but...

The Pennsylvania poll was pretty in line with the poll averages and our pre-debate poll, which found Biden+9. I should note that this sample was much more GOP (R+1, in fact) than our prior sample by party identification, so we might just have a better-for-Trump sample this time

Nonetheless, if you take the two PA polls together we've got Biden+8 with N>1400 in perhaps the most important state with just over a month until the election. This is a fairly daunting deficit in a stable race.

The debate certainly did nothing to help the president. His ratings dropped across the board. An overwhelming majority of voters disapproved of his performance, including one-third of his own supporters.

That said, Biden didn't exactly kill it either. Most voters didn't want to declare anyone a winner and Biden's ratings didn't improve compared to our pre-debate PA poll, and even fell by a lot on whether he was a strong leader.

Nonetheless, it's Trump who trails and needed a win. Instead, he lost, even if his opponent didn't excel on his own terms. Not much time left.