he told a stunned Anderson Cooper, that Trump could've told Comey to stop the investigation of Flynn, and they're still would not have been obstruction of justice. Trump has full constitutional authority to order Comey to stop that investigation.
http://dailycaller.com/2017/06/07/dershowitz-trump-could-have-just-pardoned-flynn-video/
http://dailycaller.com/2017/06/07/dershowitz-trump-could-have-just-pardoned-flynn-video/