Columbia University’s president and other college administrators have stated that the chant “From the river to the sea, Palestine will be free” is permissible political speech. On an abstract level, they are correct. It is also permissible for white supremacists to demand all blacks be sent back to Africa and all Muslims to Saudi Arabia. The First Amendment protects homophobic, sexist and transphobic speech too. But would any school permit such bigoted chants? Imagine what would happen if a group of white-supremacist students demanded South Africa be returned to white apartheid control: “From the Atlantic to the Indian Ocean, South...