There’s a quote from Robert A. Heinlein that I like to bring up:

Of what use, then, are the American Communists?

They serve one function extremely useful to you and to the country, so useful that, if there were no Communists, we would almost be forced to create some. They are a reliable litmus paper for detecting real sources of danger to the Republic.

Communism is so repugnant to almost all Americans, when they are getting along even tolerably well, that one may predict with certainty that any social field or group in which the Communists make real strides in gaining members or acceptance of their doctrines, any such spot is in such bad shape from real and not imaginary social ills that the rest of us should take emergency, drastic action to investigate and correct the trouble.

Replace “Communist” with “Conservative” and the quote works the exact same way. People don’t take on awful political views in a total vacuum. Their lives and futures got messed up somehow, and in all probability by vast forces beyond their comprehension, let alone their control. And then they went looking for what felt like real answers, and someone was willing to say to them “I’ve got the solution to your problems.”

On some level, their grievances are real. They just got sold on a lie about what could be done to fix them.