In this May 20, 2016 photo, Republican presidential candidate Donald Trump speaks at the National Rifle Association convention, in Louisville, Ky. Hillary Clinton has a message for Donald Trump: Bring it on. As Clinton's path to the Democratic nomination seems all-but-assured, friends, aides and supporters describe a candidate who is not only prepared to tune out Trump's increasingly direct attacks on her husband's personal indiscretions but believes they will eventually benefit her presidential aspirations. (AP Photo/Mark Humphrey)