Biggest issue here for Biden is this:
Biden 2020 voters: 80% Biden, 3% Trump, 17% neither/other
Trump 2020 voters: 88% Trump, 5% Biden, 6% neither/other
The thing is, the question is if its real because polls have been all over the place in terms of who is consolidating the most voters. But if it is real, it again points to the truth that Biden voters are not flipping to Trump (ironically, more are flipping the other way around here), but that Biden needs to get the more ambivalent folks who don't want Trump but don't love voting for Biden again either.
Though, Biden only getting 76% of Ds and Casey only getting 80% also presents that this isn't really a Biden specific issue either. I think a lot of these PA polls are just getting kind of messy Democrat samples.
I imagine most of those "neither/other" people come home to Biden but damn this looks like it's gonna be a close call (at least at the moment).