Can Trump afford to drop Arizona, though? The answer is yes, but what states will he need to hold on to in order to sustain the loss? Some combination of the following: Michigan, Wisconsin, Pennsylvania, and Florida. Losing only Arizona and Wisconsin would still give him a comfortable lead of 33 electoral votes; the addition of either Pennsylvania or Florida would put Biden on top. Meanwhile, Trump coming up short in Michigan and Wisconsin in addition to Arizona but holding Pennsylvania and Florida is one of a surprising number of at least conceivable scenarios that would result in a 269-269 tie, a pundit’s dream.
How likely are any of these scenarios? In Wisconsin, the polls show Biden with a very similar lead to the one Hillary Clinton had at this point four years ago, around 7 percent. But as others have pointed out, Wisconsin tends to track closely in presidential elections with Minnesota, where Biden’s lead would appear to be (barring an embarrassing failure by reliable pollsters) insurmountable. So Trump falling there is a definite possibility.