Excellent points. This year should may turn out very good!
Here's a quote from Charles Murray's "Trump's America" about Trump's supporters that bears highlighting:
There are many consequences of Trumpism that will remain with us. One of them is the end of the GOP nominating process being a contest of "Who's the purest conservative?". Here you have a major constituency within the GOP that is demanding that the government act on their behalf. These people have been Republicans and voted Republican forever; they weren't noticed because they were ignored and crapped on. Until the day, that is, where a turd hit them in the eye and they woke up. Our politics IS better for this; it's the end of the "Mr. Conservative" beauty contest that would have dismissed Trumpism as an anamoly and made Ted Cruz the "next in line".
The highlighted part is not apparent for readers over 50. Before Reagan the group in question were predominantly Dem. Clinton pulled a number of them back in the 1990's, but Perot got a chunk as well. After 2000, they have been more reliably Pub, especially outside central cities.
I'm 59, and it was readily apparent to me, lol.
muon2 is correct in his analysis. A lot of the Trump voters in Rust Belt states are, I believe, former Perot voters. A vote for Perot either time was, in truth, a Republican vote. 1992 was a very good year for Congressional Republicans; they made progress despite the Clinton EV landslide. For many of these Perot voters, Perot was the way station through which they entered into permanent Repubicanland.
How can it be apparent if you agree?
My beef is the use of the phrase "Republican forever". In any case you in the 70's these voters were for Carter not Ford, and in 1968 they split between Humphrey and Wallace (a traditional southern Dem), helping Nixon carry the election.