Barack Obama's West Virginia loss by a whopping 30 points probably won’t cost him the Democratic nomination, writes John Dickerson in Slate. But the loss does put a chink in Obama’s argument that he can unite disparate groups, since, apparently, these powers have failed him among at least one key voting block—the blue-collar whites that are Hillary Clinton's base.
In reality, he may not be "fundamentally dead to these voters," as Hillary has essentially been arguing, Dickerson says. Recent polls show Obama doing only slightly worse than Clinton among working-class whites against John McCain, and he is still running better amongst white voters than past Democratic presidential contenders have. What matters most is whether the loss affects the confidence of superdelegates.