First of all, there are hardcore Republicans who hate him.
Secondly, he says wild stuff. So did Pence, but Pence had a certain consistency built around being super christian.
Thirdly, he will say anything to get what he wants. Including directly comparing Trump to Hitler when it seemed better for him.
Fourthly, Trump is older than the average president and this guy does not have government experience OR Trump's fake sort of business experience. He's mostly just a naked opportunist.
Finally, what the hell does it say about Trump's judgement that this is his guy? (NOthing surprising to us, but to the Republicans who hate him... well.)