It may be useful to look at a history of 20th century American populist demagogues. Names on that list include George Wallace, Joe McCarthy, Father Coughlin, Huey Long, David Duke, and maybe Benjamin Tillman, though he started in the 19th century.
You can certainly argue that their millions of followers had real concerns and desperately looked to leaders who stood up against the establishment while speaking out for people like them.
Yet each of them are remembered as some of the worst villains in American history.
Is this a paradox? Unfortunately, no. Working class and rural Americans have historically been some of the poorest and worst represented groups, among the earliest hit by economic and technological disruptions and widely ignored by elites. It is also fair to say that they were among the least educated, most insular, most nativist, and least tolerant groups in the country. These are ripe conditions for anger against perceived enemies and especially toward groups that were perceived to compete for their scarce resources. Those of other races and religions, immigrants, newcomers, adherents of purportedly false doctrines and libertine morals became targets.
Politicians who articulated their discontents and provided convenient enemies to hate and target always did well, sometimes successful in alleviating local conditions, sometimes losing in ways to create more bitterness.
Occasionally, a figure arose especially gifted in these skills, an outsider even when part of the establishment party (as with Tillman and McCarthy). Their legacies are outsized compared to their actual power; legacies of hatred, oppression, bad laws, and ruined lives.
If Trump is one of these demagogues then his appeal to his followers will be a mixture of the rational and irrational, which naturally make them difficult for outsiders to fathom. One can sympathize with their needs while simultaneously denouncing their response with the same fervor given to the South’s response to civil rights in the 1960s. Critics were not making wrong and lazy assumptions about their behaviors then, but wholly accurate ones. I think the critics of Trump’s followers today are equally accurate.