Breaking: Key Trump admin aide will detail Ukraine plot to impeachment probe

06:24

The Washington Post reports Mark Sandy, from the Office of Management and Budget, is expected to defy the White House and testify this weekend in the impeachment probe. According to The Post, Sandy’s signature appears on at least one of the letters that prevented the money from going to Ukraine. Former Federal Prosecutor Glenn Kirschner joins Ari Melber on this breaking development.