On "The Sean Hannity Show" Friday night and at a Florida tea-party rally Saturday, Donald Trump elaborated on the charge that he has been making the past two weeks, namely that Bill Ayers helped write Barack Obama's acclaimed 1995 memoir, "Dreams From My Father." Yet despite what Obama-friendly biographer David Remnick had previously called the "diabolical potency" of the charge, the mainstream media have resolutely failed to investigate its accuracy. Trump all but dares them. At both stops, he emphasized the point that I make in "Deconstructing Obama": As Trump put it to Hannity, "Without that book, [Obama] is not...