As the Democratic presidential candidates gather in Washington to make their pitch to party activists this week, "liberal" is suddenly no longer a dirty word.
In recent months, virtually the entire Democratic field has tacked left -- not just on the Iraq War, but on health care, taxes, energy issues and gay rights. In each of those areas, much of the field is standing to the left of where Sen. John Kerry, D-Mass., stood in 2004, when President Bush lampooned Kerry as a "Massachusetts liberal."
"They're responding to the reality of the primaries, where the center of gravity is far to the left of the electorate as a whole," said Erik Smith, a Democratic consultant who is not affiliated with any of the 2008 candidates. "The discussion with the greater American public is just getting started. They have plenty of time to define themselves, but you don't come all the way back to the center."
For Candidates, Shift Most Pointed on Iraq
The shift has been most striking on Iraq, where none of the Democrats support President Bush's current strategy. In sharp contrast to 2004, when several candidates remained supportive of the war mission, the disagreements among the Democratic presidential candidates now extend only to how best to bring an end to the war.
A year ago, Sen. Hillary Clinton, D-N.Y., was roundly booed at the Take Back America conference when she stated her opposition to setting a deadline for troop withdrawal. When Clinton addresses the same gathering of 3,000 progressive activists Wednesday, it comes shortly after she reversed course and voted to cut off funding for the troops as a means of ending the war.
"She comes to this conference I think in a very different posture," said Robert Borosage, co-director of the liberal Campaign for America's Future, the group that is organizing this week's conference.
Appeal to Liberal Base Could Cost Them Independent Votes
With polls showing a substantial majority of voters ready to support a Democrat next year, the party as a whole appears to be in a good position to reclaim the presidency after two terms of Republican control. The party is animated in large part by its animus toward Bush, making the left feel like friendly terrain for candidates.
But some observers say that the candidates' zeal to appeal to the party's liberal base could cost them in the general election with the independent-minded voters they'll need to win.
That is a particular concern for Democrats if Republicans nominate a candidate who could claim the vast middle of the electorate -- a social moderate such as former New York City Mayor Rudy Giuliani, or a candidate with a long history of reaching out to independents such as Arizona Sen. John McCain.
"Lots of people say, 'I want a Democrat,' but when they see the particulars, they say, 'I don't want that Democrat,'" said Jeffrey Berry, a political science professor at Tufts University. "The thing that's amazing about the Democrats is that they could still snatch defeat out of the jaws of victory. The major Democrats are all now well to the left of the median voter."
Sen. Joseph Biden, D-Del., touched on this concern Sunday on ABC's "This Week." He is the only Democratic presidential candidate to have voted in favor of continuing funding for the war last month.
Biden: American Public Looking for Someone Who Can Win
"Even though the front-runners are good people and they're making a lot of news, they're still getting beaten by the Republicans [in polls], who are generically not preferred by the American public," Biden said. "They're going to be looking for someone who can win."
It's not just the war that shows the leftward tilt of the presidential field. Several Democrats are now talking about raising taxes to expand health insurance to more Americans, or to combat global warming.
All of the Democratic candidates want to reverse the ban on gays and lesbians serving openly in the military, a position that puts them at odds with all of the Republican candidates. The Democrats also want to overturn the federal Defense of Marriage Act, even though it was signed into law by Democratic President Bill Clinton in 1996.
Shift on Health Care Also Striking
An equally dramatic migration has come on health care. In 2004 Kerry offered a plan that would guarantee health coverage to all children; now, the Democrats are arguing over how best to bring universal coverage to children and adults.
"When we began this campaign the consensus on the Democratic side was that only incremental change was possible," Borosage said. "What is striking is how quickly we have made progress. So John Edwards put out a comprehensive health care plan, abandoning the question of incrementalism, Sen. Obama soon followed. Sen. Clinton has promised that she will do so over the next few weeks."
Some party strategists note that the Democratic candidates are not embracing the extreme left. No major Democratic candidate is endorsing gay marriage, single-payer health care, or an immediate and total withdrawal from Iraq -- positions that have sizeable, if not overwhelming, support among Democratic primary voters.
The Democratic Race and the Direction of the Country
Still, the Democratic candidates appear to be taking the attitude that winning the primary will virtually ensure them of winning the general election, since the country appears to be so soured on the Republican party.
"At the end of the day, it is a Democratic race. People are not happy with the direction of the country," said Chris Lehane, a Democratic consultant and a former top aide to Al Gore in 2000. "The match-ups will look very different when these other candidates come into focus."
Berry said the move to the left is in a broad sense a return to the Democratic party's roots, since the various interest groups that hold sway over the party have traditionally wanted a more liberal take on the major issues of the day.
But the candidates must balance the need to tap into activists' energy with the necessity of finding common ground with political independents.
"They'll get the Democratic base to vote for whoever the Democrats nominate, but they have to win over the independents," Berry said. "They're going to have to resist some of this leftward tug."
ABC News' Nik Bonovich contributed to this report.