Washington is broken. That’s the slogan Mitt Romney adopted in the waning days of the New Hampshire primary. And while the former Massachusetts governor trailed John McCain, his three words captured the dominant mood of the presidential campaign so far.

Every one of the leading candidates repeated the word “change” as often as possible, like some mystical chant that would levitate them to victory. A typical comment came from Barack Obama: “The time has come to move beyond the bitterness and pettiness and anger that’s consumed Washington.”

Meanwhile, a group of moderates from both parties were meeting at the University of Oklahoma and issuing a statement that made the same point. The country, they said, was failing to address critical problems like budget deficits and energy independence “primarily because rampant partisanship has paralyzed the ability of government to act and lead.”

They’re right, and the country agrees. Only one in three voters approves of President Bush’s performance; only one in four likes the Congress; three out of four say the country is headed in the wrong direction.

There are many reasons why the capital is “broken,” but the core explanation is this: Both parties calculate almost every decision in terms of their political advantage, not the public interest. They want to win points, not solve problems. They are deathly afraid of angering their base supporters, and sharing credit with their rivals, even though that’s the only possible way to get anything done.