I find it hard to take anyone seriously who cannot see the clear potential for abuse when using this kind of power, even if we might agree that having some of these people in our country is a net negative. The laziest form of this this way of thinking is the "what about" argument that try to change the subject to something similar that political opponents did that the What About-ist also considers bad. But all this does is allege that all parties are partisan hypocrites, since the What About-ist is just trying to dismiss objections to what their guy is doing, rather than seeking agreement that similar actions are wrong, no matter who does them.
We also need to pay attention to what's actually being argued by the parties involved here instead of turning this into an abstract argument about immigration, speech, and Trump. The Secretary of State has argued that he's authorized by statute to do this when a legal immigrant's "presence or activities have potentially serious adverse foreign policy consequences for our country.”
It seems pretty clear that this justification is being used because they want to avoid making this about speech they don't like. That's because there's strong precedent supporting freedom of speech for non-citizens, even if the process of vetting a potential immigrant can involve considering speech. Practically, think about how broadly this could be used if applied beyond allegedly pro-Hamas speech and activities by students. Couldn't this policy be used as a justification for detaining and deporting someone who criticized Trump's rhetoric about Canadian tariffs and making it the 51st state? We know the Trump administration is very sensitive to criticism of Russia as it attempts to woo the Russians into a ceasefire, so what about Ukrainians, Poles, or people from the Baltics who criticize the government's handling of Ukraine negotiations? This is not even to mention the way this could be used by a left-wing administration.
Do we really even believe that what some random students say is undermining our foreign policy, then? If we don't think that's a serious justification for this, then the justification is back to being that these people have engaged in speech the government doesn't like, and not even the government is trying to defend that justification because it knows it would fail.
But even if we think that legal immigrants shouldn't have free speech (which is manifestly dangerous), shouldn't we also ask why it's necessary to basically disappear these people extra-judicially? Shouldn't we deliberate a little more to avoid things like wrongly asserting the guy who was grabbed at Columbia was on a student visa? What about defying court orders? It all seems like a bit too much for some goofball students.
Whenever free speech is implicated, one of the best rules of thumb is to see where FIRE stands. In this case, they're clearly against the government:
https://www.thefire.org/news/should-government-punish-you-allegedly-undermining-american-diplomacy