It's just an impression that occurred to me while walking around the block tonight.
The analysis of the Trump voters includes the general outrage many of them feel toward the GOP elite for not being real conservative warriors, not standing up to the Democrats, not defending real Americans. This is rather like the abused children who carry more resentment toward the parent who did not defend them, even over and above the abuser. The cry goes out that they supported Romney, who wasn't a real conservative, they supported McCain, who wasn't a real conservative, they supported Bush, Dole, Bush 41 - and what have they got to show for it? They have been betrayed. Even conservative analysts, maybe even especially conservative analysts, are singing this tune.
I recalled tonight arguing with these people online 4 and 8 years ago. (And even 2000 and 2004, to a lesser extent.) I recall lots of them who were proudly stating they were sitting out because of their disapproval then. In the post-election discussions, I think there was a lot of hand-wringing that those candidates had lost because they didn't excite that part of the Republican base, who didn't turn out for them.
Also, many Trump voters are young.
Also, there are reports that many Trump voters are crossover Democrats.
Or are infrequent voters.
I don't doubt there is something to this disillusionment explanation. But I wonder how much of it is really true. Were they really go-along, hopeful, good-soldier Republicans then who are now fed up? Or is "fed-up" a default position for some of them since fifth grade, now inspired by Trump?