I'm curious why you think it's overwhelmingly his supporters that are having anti-mask rallies, etc. Do you attribute it to Trump at all? Or is it just coincidence//a byproduct of some other factor?
Of course population centers are the hardest hit as with every pandemic in the history of mankind. That'd be the case regardless of whether everyone followed the rules or not.
Semi-Related: but people do realize that even the bluest cities have a substantial amount of Trump supporters, right? DC is about the bluest place in the union, and the DC metro area is about ~25% Republican. DC proper is even about ~10%. So that means even DC has tens of thousands of Trump supporters, and about
40% of them are anti-mask mandate. So you could have every single Biden supporter following every rule to the letter... and in an apartment building of 400 people you'll on average have 100 Trump supporters with 40 of them being anti-mask.
Trump says things like "we're doing great if you just take out Democrat cities" without acknowledging that we're all Americans and that there are a substantial number of Republicans in every single metropolitan area.