Can you really choose what you believe, though? Could you make yourself stop believing in gravity or anything else you truly believe in? Could you make yourself believe in flat earth if someone told you too? The mind isn’t something so malleable that you get to pick and choose your beliefs like a salad bar. Religious beliefs are one of the hardest to change, with even those leaving organized religion ending up frequently still believing in a God of some kind.
I grew up in a religious household but open minded and science oriented, so I deconverted and consider myself an atheist. I whole heartedly agree that the world would be a better place without religion, it’s the world’s greatest con job, but let’s not kid ourselves about the spectrum of the word choice here. It’s a (lesser) reverse of the religious telling anyone that isn’t heteronormative in any way that those are choices. It’s all brain chemistry occurring in a black box that we know vanishingly little about for how much we have studied it.
I don’t think they are blaming their religion for their voting in so much as outlining that their convictions that are informed by/in line with their religion (life begins at conception) makes abortion their largest single issue. Those of honest conviction see abortion as murder, and specifically murder of a baby, and that trumps the rest of the ticket. There are plenty of grifters and hypocrites on that side too, but I would hazard that the “silent majority” on the right are the sincere convictions type.