I’ve often wondered the same thing. The overall objective of going to college is to learn to think for yourself-one reason Republicans tend to disparage them. But it doesn’t counter 18+ years of brainwashing by an ignorant parent. My unofficial brother in law B (partner’s brother but we’re not legally married) got his degree from Stanford yet he blindly believes every word Trump says. Because his father did. They’re half brothers, different fathers and B is almost 17 years older but he was livid that his sons grew up to be Democrats and being the devout Evangelical B is, he wouldn’t even tell anyone that his son converted to Muslim so he could get married. A man in perpetual denial.
We have another couple who’ve been friends for over a decade and yes, they’re Republican, but at least they see Trump for what he is. I’ve often wondered why they’re Republican since one of the foundations of the party is anti-gay and being in CA, they were finally able to marry a few years ago after being together for 30+ years. But although they didn’t vote for Biden, they said they couldn’t vote for Trump and still feel like a patriotic American. They didn’t say who they voted for and I didn’t ask since it’s none of my business but it was nice to hear devout Republicans express such views as far back as 2018—and look at how much more Trump’s done since.