Wow this guy is gross.. Switched to Republican to Democrats really is this how legislators are supposed to be in American today?
Switching was a common practice in the South since 1950th-60th at least until very recent times (and still - happens in not so small numbers). And there are switches in opposite direction too. It's another matter, that this was done purely out of revenge. But, probably, the legislator in question was of opinion, that Republicans were of more positive view to his interpretation of what really happened... He, surely, wasn't a big fan of identity politics or SJW-culture, which dominates Democratic party of late.
He got voted out by more than just democrats. It was almost unanimous.