Trump has now spelled out how he will make Mexico pay for a border wall. He will put the squeeze on Mexico until they cough up the dough. The squeeze will include tariffs on imports, fees on visas, a threat to cut off visas altogether and, above all, a threat to require proof of citizenship or legal residency to wire money out of the country. Mexican immigrants to the US (legal and illegal) send remittances home to their families that are an important form of support. Trump will threaten to cut them off.
The Washington Post has commented, sensibly enough, that there is a political flaw here in that Trump will be threatening a shutdown of remittances unless Mexico helps us -- to dry up the source of those remittances altogether. Hm. . . .
But less convincing is that attempt to argue that the attempt is overly intrusive and will not be enforceable. Why not? How hard can it be for Western Union and other such services to ask for an ID whenever they wire money out of the country? If liquor stores and airports can ask for ID's, why not money wire transfers?
I say this as one who hates and despises Trump and everything he stands for, but let's be realistic here.