In trying to explain our political paralysis, analysts cite President Obama's tactical missteps, the obstinacy of congressional Republicans, rising partisanship in Washington, and the Senate filibuster, which has devolved into a super-majority threshold for important legislation. These are large factors to be sure, but that list neglects what may be the biggest culprit of all: the childishness, ignorance, and growing incoherence of the public at large.