From Donald Trump and his top surrogates to the right-wing media and its engine rooms of outrage in the blogosphere, Hillary Clinton's opponents are ramping up efforts to sow doubt over the candidate's health. The campaign -- which goes back years -- has escalated to shouting over the summer, as Trump spiraled in the polls while mostly failing to connect with voters outside his base demographic. Now, as the race enters a crucial phase, there has been a growing push to fundamentally undermine Clinton's candidacy. Much in the way "birthers" (Trump was among the most prominent) sought similar ends by...