Legal experts battled with Republicans over impeachment both on and off Capitol Hill on Wednesday, as the House Judiciary Committee heard testimony from constitutional law scholars on the legal grounds for impeaching President Donald Trump.

Democrats on the committee tapped three scholars to testify about Trump’s conduct: Harvard Law School’s Noah Feldman, University of North Carolina School of Law’s Michael Gerhardt and Stanford Law School’s Pamela Karlan. In turn, Republicans brought in George Washington University Law School professor Jonathan Turley.