Null will perpetually use the free speech absolutist argument till the site dies. I see his point but I don't think he has enough foresight to see where this stuff is going.
You could either ban them, or let them post. There's no "forcing them off site" for these types. They crave negative attention.
Also, devils advocate but banning people based on characteristics would just make this place like something awful post 2011, essentially a echo chamber. But free registration this time.