Both the Republican National Committee and the Democratic National Committee have field days every time a candidate from the other side opens their mouths. To the GOP, anything a Democrat says is liberal extremisim. To Democrats, a Republican's utterances are radical conservatism. It's standard hyperbole for a primary season: Both sides have to play to their base to get to a general, and both sides are ready to pounce when that happens.

Many pointed out, through the course of last year, that social conservatives lacked a candidate they could call their own. Until the rise of Mike Huckabee, none of the top candidates had a particularly strong or appealing religious background. One thing no one mentioned: Liberals didn't have a candidate either.

Sure, everyone called Hillary Clinton, Barack Obama and John Edwards liberals, but all of them appealed to different segments of the traditional liberal coalition. As conservatives could not find a candidate around whom to rally, so too did liberals lack a single candidate who carried, if not the perfect platform, at least the aura of the old fashioned liberal mantle.

In what is increasingly looking like a long-term contest, Obama is now making a concerted effort to pick up that legacy. He hasn't come out with radical new positions or been spotted shamelessly pandering to the base, but recent endorsements, and in recent speeches, Obama has actively sought to associate himself with liberal lions of the past.

Ted Kennedy helps. Endorsements from Caroline Kennedy and California First Lady Maria Shriver, both of whom attended a mega-rally on the UCLA campus yesterday, help as well. Yesterday, at another huge rally in Minneapolis, Obama himself tried the association game with one of the left's true heroes. "When I first got to the US Senate, I opened up the drawer of the desk where I was assigned. And it has the names of some of the great senators who have served," Obama told the crowd, per NBC. "They carve their names in their own hand into the desk drawer, and one of those names was somebody who shared with me this belief that change doesn't happen from the top down. A guy named Paul Wellstone."

Wellstone, whose plane went down in northern Minnesota just weeks before Election Day 2002, is an idol to Minnesota Democrats. A professor by training, an unabashed defender of the left's causes, Wellstone's mark can still be seen around the state, where his campaign's bumper sticker -- green background, white letters and an exclamation point -- is not an uncommon sight, even six years later. Obama wants that association, saying Wellstone "helped to create a movement here in Minnesota, because he believed in you the way I believe in you. And this is part of that movement of change all throughout America."

Most exit polls in early contests have showed Obama outperforming among those who call themselves liberal, while Clinton has generally underperformed among the same group. Courting the lefty base is a smart way to get through a primary: Those who call themselves very liberal make up as much as one fifth of the electorate. Doing so in a way that avoids dramatic lurches to the left is a smart way to look toward November.

Obama hasn't quite wrapped up the liberal base yet. Florida liberals actually preferred Clinton by wide margins. Though perhaps the Illinois Senator is on the verge of scoring another big endorsement from a liberal heavyweight: Former Vice President Al Gore, who is said to be worried about jinxing Obama's campaign with his nod, talks with Obama on a regular basis.

Taking a look at Obama's advertisement played during the Super Bowl, though, the images flashed on screen to associate with global warming sure look like they came straight out of a certain Gore-associated movie. Check it out for yourself.