"Authoritarians...are only too aware that universities are primary sites of critique and dissent"

Certainly true in recent decades, although at other times universities have been complicit in tyranny, rather than sites of resistance.  If Trump wins (which is still a very live possibility), he has various tools at his disposal to undermine even the wealthy private universities, ranging from withholding federal aid on (fake) grounds that universities are discriminating against Jews, to taxing university endowments, to conditioning federal aid on maintaining artifically low tuition.