Of the 200+ Democrats in the House, only one defected to Bush's side. Without bipartisan cover on an issue where Democrats have historically had the most credibility, and without enough Democratic support to make up for differences within the GOP caucus on how to make the finances work out (higher taxes? more debt? benefit cuts?) the Republicans simply couldn't get a plan through. Social Security was saved.
That was the point when I regained my optimism about the Democratic Party. Pelosi wouldn't do on Social Security what her predecessor, Dick Gephardt, had done on the war -- get bullied into supporting disastrous policies by an overconfident president. (Harry Reid, for his part, did a similarly good job in the Senate.) Pelosi and Reid dealt George Bush the most devastating legislative defeat a president has had since the failure of the Clinton health care plan in 1994.
So when 2009 comes around and it's time to pass health care reform and whatever other domestic policy initiatives we want, we can be confident that the House side of the game will be in good hands.