I had almost lost interest in the debate last night when Tim Russert asked Hillary Clinton about New York Governor Eliot Spitzer's proposal to give driver's licenses to illegal immigrants:

Hillary's answer was problematic not only as a matter of policy, but also for its slipperiness. After getting drilled by her two main rivals for the better part of an hour and a half for being a "doubletalker" (Edwards) and "secretive" (Obama), Clinton played right into those charges by trying to have it both ways. You could see from the stare she gave Russert when he re-asked the question she knew she'd been put in a spot, and she wasn't the least bit happy about it.

In general, Clinton took a pounding last night but did a competent job of defending herself. Chris Dodd hit her on electability, Obama took swipes at her on Social Security, but it was John Edwards who did the best, most direct job of framing the choice for Democratic voters. In particular, Edwards' critique of Hillary's trustworthiness was key. If you talk to people in Barack Obama's camp, they believe the issue of "trust" is one of the main fulcrums around which this race is going to turn - ultimately, in their opinion, away from Hillary and in favor of Barack.

But it was Edwards who reached out last night to try and grab the mantle as the candidate Democrats can trust - and he seemed to do it somewhat effectively. The reason the "trustworthiness" charge is so potentially potent is because it dovetails with - or cuts against, depending on your perspective - the argument for real change, which is what Democrats (and Republicans, for that matter) are yearning for this year.

Edwards' accusation is that Hillary is an entrenched part of a corrupt and broken system, and that you simply cannot trust her when she says she's an agent of change. That is a powerful message that probably rings true to many Democrats and arouses deep-seated suspicions about her. Furthermore, it makes her slogan - You can't have change without the "experience and leadership" - seem like another example of hollow Clintonian parsing and triangulation.

Again, this is the argument Obama should be making against Clinton, but Edwards was the one who took the lead. That doesn't mean it may not still benefit Obama in the end, but for the moment the anyone-but-Hillary portion of the Democratic party watching the debate last night found their candidate in John Edwards.

I'm a firm believer that debates matter very little as individual events. A single debate on a little-watched cable channel where nothing spectacular happened is simply not going to change the dynamics of a race overnight. That being said, last night's debate did perhaps offer the opening salvo in what will become a recurrent theme on the campaign trail that has the potential to alter the Democratic race in a significant way as Edwards and Obama hone in on the issue of Clinton's trustworthiness over the next 65 days.