I wonder if this will have a similar effect to Brexit. When the Brexit referendum outcome was Leave, I was in Cambridge. The head of one of the largest departments at the university told me the week following the result most applicants who had recently accepted tenure-track offers changed their minds and declined. Several prominent faculty members also began making plans to move to the EU. Over time, however, these effects have become less noticeable. But major funding uncertainty is a big deciding factor when you are starting your career.
I have two friends in Europe now who were going to send their kids to American universities in the next couple years. Both decided not to based on current events.