Building a fence has nothing to do with that. If Texas had setup a federal border crossing, that would be illegal. If Texas had that fence constructed in such a way that a federal border crossing were blocked off, that would be illegal. A natural land border augmented with a fence isn’t an international incident and you don’t need permission from the federal government to do that.
Building a fence has nothing to do with that. If Texas had setup a federal border crossing, that would be illegal. If Texas had that fence constructed in such a way that a federal border crossing were blocked off, that would be illegal. A natural land border augmented with a fence isn’t an international incident and you don’t need permission from the federal government to do that.