At least in my area, there are pockets of (relatively) new immigrants that have MMR vaccination rates at around 30% (that's very low, much lower than the anti-vaxxer population could account for imo), and the reasons for that have nothing to do with MAGA/MAHA as far as I can tell.
It's an entirely different problem (that needs solving), and pretending that this is simply the by-product of uneducated crazies on the internet feels like it's over indexing on a loud and flashy but ultimately small part of the problem.