Well, you might be surprised to find "most" New England fans are not "nut-job leftists" though it is likely true there are more of them by a percentage than there are in other places.
Even conservative places like Texas, Florida, and the military have their own populations of "nut-job leftists".
Well of course; no place is “perfect” either way. How do you think I feel being in central MD? Chances are that NEers - metro Boston - are supplying plenty of leftism to their teams.
My father and his whole big family grew up in ME/NY, and many of them still live there, I worked and lived there a while. Plenty of leftists (not in HIS family, but even my aunt-by-marriage still in ME is a Canadian leftist who keeps fawning over the Moslems in their neighboring Lewiston).