They ain’t gonna relinquish their US citizenship – it will cost them too much money (it’s shocking the penalty the US government exacts of anyone renouncing their citizenship). Plus, they won’t be willing to give up all their gummint freebies. They’ll just live the expat life until the next big lib is running for office, when they’ll come back to rabble-rouse and vote for said lib.
BUT – one can at least dream and smile at the idea of a tide of libs pouring across the border…. Ahhhh!