Actually a lot of them don't. It's weird but a lot of polling has found that a big chunk of Trump supporters somehow believe that all the outrageous things Trump says are somehow just for show, or are sarcasm, or just a joke. I'm not talking about the maga hat, rally goers, but the more average Trump voter who says "the economy" is their top voting issue.
Trump couldn't win a national election with just maga. Somehow getting the more normal Trump voters to believe he might actually do what he likes to talk about doing, might really help.
Why would this make PBS and NPR sad?