This is sort of the incredible thing: white Americans really think America sucks right now, but financial data shows us white Americans have never had it better! The resentment is social! Lots of us don't want nonwhite Americans to have it better!
Historians of this era will spend a lot of time studying social resentment, especially in older folks, and how it's played such a central role in politics.
This is definitely part of it. It feels like these people have been pushing back against progress forever and LGBTQ+ acceptance is the final straw for them. Just monstrous assholes.