From left, Constitutional law experts, Harvard Law School professor Noah Feldman, Stanford Law School professor Pamela Karlan, University of North Carolina Law School professor Michael Gerhardt and George Washington University Law School professor Jonathan Turley testify during a hearing before the House Judiciary Committee on the constitutional grounds for the impeachment of President Donald Trump, on Capitol Hill in Washington, Wednesday, Dec. 4, 2019. (AP Photo/Andrew Harnik)