A coalition of 16 states, including California and New York, on Monday, challenged President Trump in court over his plan to use emergency powers to spend billions of dollars on his border wall.
The lawsuit is part of a constitutional confrontation that Mr. Trump set off on Friday when he declared that he would spend billions of dollars more on border barriers than Congress had granted him. The clash raises questions over congressional control of spending, the scope of emergency powers granted to the president, and how far the courts are willing to go to settle such a dispute.