I'm not sure when you were a professor, but things have changed a lot in the just the past four years. My sister is a professor at a California public university and unless you have a Nobel Prize (or are prominent in some other manner), everyone is being scrutinized. Tenure no longer means a job for life. It means they need to have cause to push you out (no one actually gets fired) -- whereas w/o tenure they needn't have any cause.

Apparently a common tactic is to increase your teaching load so high that no reasonable human can do it. These people either go to a different university or leave academia disgruntled.