If Barack Obama loses next November, we'll look back on Sunday -- July 31, 2011 -- as the day he became a one-termer.

He demonstrated the one key quality common to all unsuccessful leaders: Haplessness.

In the most confrontational partisan moment of his presidency, Obama ended up looking remarkably powerless. He didn't get his way. To put it mildly.

The deal he endorsed on the debt ceiling will long be an object of debate for both right and left. There's so much for everyone to dislike in it that people are lining up to rage against it, even though it will surely pass.

But there won't be much debate over the fact that just 10 days after Obama insisted he would not agree to any deal without tax hikes -- "Don't call my bluff, Eric," he warned House Majority Leader Eric Cantor -- he assented to a deal without any tax hikes.

"I'm going to the American people on this," Obama told Cantor. And he did. He gave three press conferences and a nationally televised prime-time address from the Oval Office. And over the course of the week he did so, his poll numbers plunged 10 points.