Interesting I had seen something a few months back that said the entire border was already under legislation along the lines of an easement in place throughout the US and the feds could actually do as they pleased within a certain distance of the border. I don’t recall how far though...maybe 150 ft or yards....no I don’t remember.
See if I can find it.
Roosevelt Reservation
It’s a 60 foot strip of land on the U.S. side of the border with Mexico and was established in 1907 by Presidential Proclamation and is under control of the Federal Government; it was established to keep the land free of obstructions to prevent smuggling over the border.
A 60 foot strip of land on the border under control of the Federal Government? There’s the right of way for the wall...