Trump and his coded plea for someone to assassinate Hillary Clinton. Why hasn't he been arrested or at least investigated by the Secret Service?

Trump's Damnable, Dangerous 2nd Dog-Whistle To Shoot At Clinton. Vol. 6 of my new series #TheCloserGQ pic.twitter.com/AytcRbpTDA

— Keith Olbermann (@KeithOlbermann) September 21, 2016