Just as a follow-up, I looked at his CV (which is available here) and I don’t see anything that would be an obvious red flag before the time of his initial hiring, or even the time of his promotion to associate. However, by the time he was promoted to full he had a bunch of highly questionable publications behind him, including whiny papers in Academic Questions, which is rag published by the execrable reactionary self-named National Association of Scholars, and a couple of similarly whiny books about how horrible it is to be a conservative in a university. I don’t see how he was promoted to full professor on that record.
There is also evidence that he padded his CV, which is another one of those violations people can use to sack tenured faculty. I assume his success so far, and his soft landing, mean that he has some people backing him up in the state legislature.