It might stop trucks with Texas plates from turning up with cartel logos emblazoned on the side while they attack the city hall and police station in a place less than an hour’s drive from the border. That is, it will work both ways, because these gangs have staked out territories on both sides of the border.
Trump is right. They’re terrorists, we need to kill them when they attack, deport them to Mexico if we find them living here, and if they’re US citizens...which many probably are...sweep them up and either jail them for the rest of their lives or execute them. They have done horrible things.
You are making this unnecessarily complex. They are terrorists, kill them. Doesn't matter where they live.
(BTW anyone who attacks out border should be killed)