Time for a year-end look at five moments that fundamentally altered the way the Democratic race has played out:

5. September 26 -- Edwards accepts public financing. Casting it as a move to ensure openness and a way to shut out lobbyists and special interests, John Edwards declared in late Spetember that he would accept public financing in his bid for the Democratic nomination. The decision gave him access to millions he might not otherwise have raised, but it also severely curtailed spending. Edwards, once seen as the obvious yin to Hillary Clinton's yang, has been marginalized to some degree by Barack Obama. And while Clinton and Obama each raised upwards of $75 million in the first three quarters of the year, Edwards has struggled in a distant third place.

Edwards' decision hurt him in several ways. Aside from curtailed spending in early primary states he needed to win, he also lost support among many of his one-time fans in the liberal blogosphere. Kos, for one, said that the acceptance of public money meant Edwards was not viable, and though he maintained good relations with the netroots, Edwards needed them to be for him in a much stronger way.

4. August 4 -- Clinton attends YearlyKos. The liberal netroots, who in 2006 helped raise million for the Democratic Party and claims responsibility for victories by several second-tier Democratic congressional hopefuls who pulled off big upsets, had their knives out for Hillary Clinton early. Unhappy with triangulation and furious with what they saw as timid moderation, the netroots wanted an unabashed progressive who would fight for their cause; it is little wonder that John Edwards had won online straw polls at DailyKos for more than a year.

But Clinton decided to attend the largest gathering of liberal bloggers of the year, showing up at YearlyKos in Chicago and held a breakout session to get to know a new set of opinion makers in the Democratic column. Clinton's moves to placate the netroots -- communications director Howard Wolfson fought Bill O'Reilly over YearlyKos; Clinton earned the endorsement of netroots hero Joe Wilson and announced it on a conference call with bloggers; in the Senate, she worked on a bill to provide paper trails in voting machines -- had a hugely important effect: The netroots still didn't like her, but at least they didn't hate her.

Whether it was DailyKos or the Democratic Congressional Campaign Committee that got certain candidates elected is subject to debate. But it was certainly the netroots that brought down Democratic Senator Joe Lieberman in his primary last year. By making sure lefty bloggers did not hate her, Clinton escaped what could have been a blogosphere-wide effort to bring her down.

3. October 30 -- Clinton stumbles in Philadelphia. In early debates, Hillary Clinton provided no zingers, no great lines and no winning moments. But she was the front-runner, and because she did not lose, she won. Again and again, Obama, Edwards and others tried and failed to land a punch. It was left to Tim Russert, moderating a debate in Philadelphia the day before Halloween, to throw Clinton off her game.

Clinton seemed on her way to another flawless debate performance until Russert asked her whether she agreed with New York Governor Eliot Spitzer's decision to grant driver's licenses to illegal immigrants. Clinton hemmed and hawed, offering what her opponents criticized as two answers in two minutes. The sheen began to come off the impenitrable armor of the inevitable candidate.

2. November 10 -- Obama shines at Iowa Dem dinner. Fewer than two weeks after the debate in Philadelphia, Clinton had the chance to right the ship. The Iowa Democratic Party's Jefferson Jackson Dinner presented the opportunity to give a big speech, fire up the crowd and show organizational strength. But Clinton's efforts were outstripped, again, by Obama.

Clinton, speaking second-to-last, delivered a solid speech ripe with red meat for her fans crowded into an old hockey arena in downtown Des Moines. Obama, speaking last, put every candidate to shame with what many considered his best speech since his address to the 2004 Democratic National Convention. And while Clinton had many friends in the audience, Obama had more -- Joe Biden made light by saying hello to Iowa and hello to Chicago.

Riding high in national polls, leading big in Iowa and New Hampshire, Clinton's Philadelpia stumble opened a window through which Obama entered at the Jefferson Jackson Dinner. Now, Clinton's ten-point lead in Iowa has turned into a tie in the latest RCP Iowa Average. Her huge lead in New Hampshire has also evaporated, and while she leads the latest RCP New Hampshire Average, she has trailed Obama in recent polls. Clinton has even seen her national lead shrink.

1. January 16 -- Obama files exploratory committee. Conventional wisdom in 2006 and before was that Hillary Clinton would run away with the Democratic nomination. It was to be less a campaign than a coronation. But with the entry of Barack Obama, a freshman senator who nonetheless enjoyed unbelievable support, a hefty fundraising capability and the aura of one who could do no wrong, the calculus fundamentally changed.

Clinton's team already anticipated John Edwards' angle -- he would cast himself as the outsider versus Clinton, the ultimate insider. But Obama was more of an outsider than Edwards. He was new, fresh, and called for a fundamental change in the American political system in a way that Edwards simply couldn't match. The Clinton machine was seemingly blindsided, especially after Obama began drawing crowds numbering in the tens of thousands to rallies. His entry sucked oxygen out of the room, dooming second-tier candidates to also-ran status, a fate even Edwards might face.

Obama's audacity of hope, a theme to which he has stuck throughout the campaign, and the sheer audacity of a freshman senator running against a party legend, changed the Democratic race more than any candidate's entry -- save, perhaps, that of Al Gore -- could have.

The Democratic race is much more stable than the GOP race -- unlike yesterday, today our top five deals with just three of the candidates. In all likelihood, the race is still Clinton's to lose. But given the momentum Obama has built, thanks in large part to the Jefferson Jackson Dinner and Clinton's weak debate performance in Philadelphia, he has the opportunity to steal the nomination.

No matter who wins, Obama's was the game-changing campaign, and Clinton has to hope that she will either get her momentum back or that Obama's charge is just too little, too late.