For most professors in the humanities (especially anthropology and history) I have seen a radical tendency. Anarchism is more common than marxist socialism for sure but I have brought up my explicit marxism to multiple professor and not been directly challenged on it. The response has typically been, "marxism is a valid analytical perspective but limited in certain capacities" at worst. There has only been one professor I would describe as anti-marxist.

I have only had one professor who was explicitly marxist but he was a trot and would regularly visit mexico to mourn him. Interesting guy