Fire his or (or her, depending on how it self-identifies that day) sorry ass.
All of my criminal justice professors we gray haired, retired law enforcers, each with decades of experience on the street. This guys mere age and obvious lack of true bonifides would have made him a profound joke at a university that is interested in more than getting a student’s money.
People should not be fired for what they say or do on their own time unless that action renders them unable to physical do their job.(such as being in jail.)
That said the bad teacher’s opinion does undermine the reliability of his related profession, thus the university has a vested interest in not letting it get out that their students will be taught this lawless hate instead of the law he is suppose to teach.