Mahmoud Khalil and Free Speech for non-citizens

For context, Mahmoud Khalil has been detained for possible deportation because of the Trump Administration's ire over Khalil's participation and organization of Columbia University protests against Israel's genocide in Palestine. Despite being a permanent resident and being married to a US citizen, the deportation was justified by "national security concerns" and his "consequences for US foreign policy."

My understanding of free speech is that it's a universal, inalienable right -- in fact, the Declaration of Independence asserts the God-given nature of this fundamental freedom. If US policy was morally consistent, should it not be protected to the highest extent even for non-citizens? At the end of the day, if free speech is a human right, one's citizenship status should not give the government the ability to alienate that right. I understand that it's possible for non-citizens to promote an agenda among voters that is objectively against US interests...but that already happens on internet spaces, so it's quite literally impossible for the voting populace to be immune to foreign opinions on their politics. Is there really a good argument against free speech protections for non-citizens?