Notwithstanding all of the points already made in the comments here, a large number of these people are informed (I use that term loosely) wholly by right-wing media sources anyway, which happily lie to them about the causes of their problems as well as the effects of what their politicians are doing. In short, they don’t believe GOP policies are personally harmful to them because Fox news is constantly blaring at them that the price of eggs and gasoline, why they can’t find a doctor, why they haven’t had a raise in 20 years, etc. is actually all Joe Biden/Kamala Harris/AOC/Obama’s fault, or because the Mexicans up the street stole all the jobs, or whatever.

These people live in a constant roiling, seething ocean of propaganda largely comprised of utter falsehoods that are nevertheless plausible sounding to the uneducated, and they believe all of it.