He sounds like a gadfly.
But espousing unpopular thoughts is not “behavior.” It is free speech and so long as the student does it respectfully (not interrupting others while speaking, not yelling, etc.) it should not be a problem.
But the one thing liberals cannot stand is unpopular thoughts. Conform or die.
Once I as in a class and the leader gave an example of this horrible experience having to do with a buyer finding a body that had been there for days. Just that year my estranged husband was found just like that. I sat really still and controlled myself , I managed to not run screaming and crying from the room. After class was over, I went up my best friend and just collapsed on the shoulder crying. I got comfort but the teacher was really wondering what was wrong with me. My best friend handled it all for me I never missed a class I got over it I handled it after that within myself. If you treat a problem like it’s a big mountain it will be a big mountain.