Old Buildings and land are relatively cheap.
It’s the planes, ships, and payrolls that would eat through all those billions in a matter of days.
Also pretty sure the US wouldn’t care and just keep the bases they want….what would a new country with no military do about it?
And tarrifs work both ways. New ports can be built.
California produces 460,000 barrels of oil a day and uses 1.8 million.
Granted it would suck to have to look at a border wall every day, but I would support it. Don’t need illegal California immigrants running through my backyard all the time.