Regarding your last paragraph, this is exactly what happened with the Dixiecrats in the 1960s and was supposed to happen with the Reagan Democrats in the 1980s, but didn’t.
The future demographic realignment will happen along racial and ethnic lines. I expect that Texas and Arizona will be back in the D column within 20 years given the growth of the Hispanic communities there and their now solidifying alignment with the Democrats. Unless by some chance a Republican comes along and shows them the way to Conservatism and away from the identity politics demagaugery the Dems have been seeding them with.
I am very afraid that you are right. Although most Hispanics that I know are far more socially and economically conservative than most Democrats, they still seem to be lining up to join the Democrat plantation.