If "older, blue-collar whites" is code for "people who primarily vote on the basis of white identity politics," Democrats have gotten their message to them, and that's why they vote R.
One thing that bothers me in this cycle is that we're seeing a lot of understanding pieces on white backlash, talking about how they're facing economic insecurity and no one seems to care so naturally (if regrettably), they're scapegoating minorities, etc. But it's not like there was no racial animosity during the period that they're supposedly nostalgic for. Like, "oh, if you were white, you used to be able to graduate high school and be entitled to a high-paying job that allowed you to buy a house and two cars and have a stay-at-home wife, etc." So OK, that happened in some places at some times, I guess, but racism was even worse then than it is now. It's not an explanation.