The attorneys general of Maryland and the District of Columbia filed a federal lawsuit Monday against President Donald Trump, alleging he violated the Constitution by retaining ties to his sprawling global business empire and by accepting foreign payments while in office. Maryland Attorney General Brian Frosh joined District counterpart Karl Racine at a news conference in announcing the lawsuit filed in U.S. District Court in neighboring Maryland. Much of the case is focused on allegations that Trump’s real estate and business holdings violate a little-known emoluments clause of the Constitution. The provision bars the president and other government employees from accepting foreign gifts and payments without congressional approval.