I feel like it's a case where you the stereotypes exist to backwards explain any outcome that you want.

Like NYC and Boston famously have a "fuck you, mind you own business" stereotype contrasted with a rural stereotype expectation of cooperating for the community.

I think the higher order bit is Repliblicans pushing an anti-institutional agenda more recently (including Trump saying bad things about historically conservative institutions like the FBI) which naturally lines up with an antivax agenda.