Larry Summers was the President of Harvard, Bill Clinton’s Treasury Secretary and a top economic advisor to Barack Obama. He was once thought a shoe-in to replace Ben Bernanke as head of the Federal Reserve. But last Friday, Montana Senator Jon Tester became the fourth Democrat on the Banking Committee to indicate opposition to Summers. In July, 20 Senate Democrats sent a letter to the President extolling the credentials of the Fed’s Vice Chair Janet Yellen. So, when Summers took himself out of the running yesterday, Noam Scheiber wasn't surprised. The senior editor at The New Republic has more on what that means about the realities of Democratic Party politics.