One thing you may have missed even if you’re following the election really, really closely is that Americans get to vote this November to decide control of not on one or even two but three bodies: The president, the Senate, and the House of Representatives.

◼ How the 2012 Election Is Stacked for the GOP - Jonathan Chait/New York Mag

In practice, then, Democrats have just one election that gives them a remotely fair chance to win: the presidential election. They have no chance to control the House or to wield effective control over the Senate. The whole weight of the party’s agenda — protecting health-care reform, progressive taxation, and everything else that might be mowed down by Republican-controlled government — rests on Barack Obama’s shoulders.