From the Chicago Maroon (Nikhil Jaiswal, Finn Hartnett, Solana Adedokun & Michael McClure):
Seems quite right to me (though I think the university should have removed the protesters more quickly), and would have been so even at a public university governed by the First Amendment.
Of course, the same rules can and should be applied to any hypothetical pro-Israel sit-in, anti-abortion sit-in, anti-police-brutality sit-in, and so on. Indeed, one might ask, “What should happen to anti-abortion students who decided to engage in a sit-in in the medical school admissions office?,” and apply the same answer—they should be arrested as trespassers, I think—to any other group of trespassers, regardless of viewpoint. There is no First Amendment right to occupy university offices, and I don’t think broader free speech or academic freedom principles include such rights, either. Free speech principles secure broad rights to demonstrate in public spaces, generally including public spaces at universities. But they don’t secure a right to demonstrate inside university offices.
Government offices, and space inside government buildings more broadly, are “nonpublic forums,” where the government can restrict speech so long as the restriction is viewpoint-neutral and reasonable in light of the purposes for which the place is being operated. Requiring that admission offices be just for office employees and students invited for admission-related purposes is eminently reasonable. To the extent that a private university voluntarily accepts restraints such as those that the First Amendment imposes on public universities, it also retains the power to make sure that its offices are used for their intended purposes, not for speech by whatever group wants to use them.