Things like "wearing masks" and "getting vaccinated" didn't have to be political

I think that's actually not completely true. Vaccines and personal mandates like mask wearing and seatbelts have always been somewhat political, but mostly among the anti-establishment libertarian "government bad so I don't wanna" types. The Republican party had already incorporated the parts of the Tea Party that could be polished into something publicly acceptable into their ranks but that wing of the party could have been squashed to background noise if the head of the party had decided to. Unfortunately "government bad" is an easy win with an anti-establishment base and the leader of their party is all about easy wins with the base.