Even if they build the wall, couldn't Mexico just take it down? Like legally they're allowed to reject it? Who's actually responsible for the legal side of this? I don't get it. To build something you need building permission. Can the US government be denied that? by their own court, by Mexico's or maybe someone else?
Like any wall or fence between two “properties” you build it on your property unless you have agreed with the other owner to place it over the property line. You don’t need the other owner’s permission to build it on your side of the property line.
This project is something to keep the attention away from all the harm the administration has and will do concerning the right of minorities defined by race, gender, sexual orientation, religion and others; the environment, and reason. Bottom line, is an exercise in futility at best.