We're quite far from the scale tipping in that direction, but it makes me curious about whether the US government has the legal authority to say "educating foreigners is no longer in the national interest, therefore it is no longer a valid reason to remain in the United States" and decimate the foreign student population essentially overnight.
It can almost certainly unilaterally revoke all the visas. Why the US wants to blow up its own higher education system would be beyond me, though.
Something like this wouldn't surprise me at all, given the current political atmosphere.