Updated at 4:56 p.m. ET
President Trump used his veto pen for the first time Friday, after Congress tried to reverse his national emergency declaration and rein in spending on a wall along the U.S.-Mexico border.
Congressional critics do not appear to have the votes to override Trump's veto. So, as a practical matter, the administration can continue to spend billions of dollars more on border barriers than lawmakers authorized, unless and until the courts intervene.