@evan I agree it's an important and wrong act in itself. Now is far enough, and this is a good place to draw a line and say "This is wrong. Stop." I also think that it is a precursor to worse behavior.
Speech supporting Palestinians or protesting Netanyahu's genocide in the US is less popular than other forms of opposition to US policy, and it can be painted as "support for Hamas" or "anti-Semitism", even if it is neither. The press are not reporting what Khalil said or did, just that he is Palestinian, and led student protests. The gaps get filled in as the reader wants.
But if this trap door is opened, the next trap door will be some other oppositional speech that is unpopular - maybe protests to immigration policy or government cuts end up being reason to rescind green card status for security reasons.