https://slate.com/news-and-politics/2019/02/national-emergency-tragedy-trump-wall.html?fbclid=IwAR039-PfHj06aP58eGmOHry3rc7ZjwpcwsyXYmVQ47cz1X_3diH47OhcFpw
"Playing out these arguments in court will take years—all in addition to the inevitable lawsuits should the government try to condemn through eminent domain the private property it needs to build the wall. And even if the challengers prevail, all of this energy will have been necessary only because of a presidential determination to treat as an “emergency” a set of circumstances that is anything but. Congress could—and should—put a stop to this nonsense now. Under the National Security Act, it can nullify a declaration of national emergency. It can also just pass a statute providing that, for purposes of building a border wall, no funds shall be reallocated pursuant to whatever statutes Trump cites. Any self-respecting legislative branch would stand up to Trump’s aggression by a vote so overwhelming as to overcome any veto threat. Such resistance, unfortunately, is altogether unlikely."