Watching this campaign unfold reaffirms how much it would have benefitted from a serious, centrist third-party challenger. It would have been so clarifying to have an independent voice calling out Mitt Romney for running a campaign that consists of decrying the last three and a half years of the Obama presidency, while offering to reinstate the very same failed policies that made the eight years of George W. Bush a disaster that President Obama has spent most of his time cleaning up. And it would have been equally clarifying to have an independent challenger calling out Obama for failing to put a credible, specific economic plan on the table — at the scale of our problem — but relying instead on a campaign that amounts to a series of discrete appeals to each of the Democratic Party constituencies. It feels like a ground war with no air cover.