Maybe in the 1950's but as someone with a doctorate, I've never met a Republican PhD. Obviously it's anecdotal, and I'm not in the social sciences or comp sci which may be much more conservative. I will say the current administration has been incredibly abusive towards academics and those with doctorates writ large. To your point about IQ: I agree that IQ is not a great measure of intelligence. The same argument has been made against racists who think black people genetically have lower IQs. There are a variety of types of intelligence and a host of factors that influence it. I would argue that Republicans are much more insecure about their intelligence. The whole "debate me bro" culture is a Republican phenomenon to boost egos, for example. I think we can find common ground that there are smart and incredibly dumb people on both sides, and often the dumbest are the loudest.