AP Photo/John Minchillo Republican presidential candidate Donald Trump works the rope line during a campaign stop at the Savannah Center, Sunday, March 13, 2016, in West Chester, Ohio. A number of observers have said Donald Trump’s march to the Republican presidential nomination is a case of chickens coming home to roost. And it’s true: The GOP has for years been playing to white resentment, and Trump has just exploited that potential more aggressively than anyone else. From this standpoint, the Republican Party’s leaders have no one to blame but themselves for the hijacking of their party. But let’s play a little “alt” history and imagine that several years ago, Trump began calculated moves to run as a Democrat. Let’s imagine also that Beau Biden had never developed brain cancer, and that his father, Joe, had decided to run for president, so the “mainstream” Democratic vote was more divided. Planning to run as a Democrat, Trump would have avoided backing the “birther” movement, but...