Something remarkable, almost magical in its resilience, will take place on Jan. 3. Thousands will gather in schools, churches and public libraries across Iowa to caucus. It’s an imperfect, curious system. Nonetheless, during the evening hours, when presidential candidates and campaign staff are relegated to the sidelines, the circus of democracy will be suspended and something approaching actual democratic deliberation will unfold. But who should the voters of Iowa–and then New Hampshire, Nevada, South Carolina and the states that follow in this crowded primary season–select as the Democratic Party’s standard-bearer?

The administration of President Bush has slashed and burned its way through Iraq, our Constitution and the remnants of the social safety net. It has pursued imperial aggression, lethal incompetence and crony capitalism as if they constitute official policy, leaving the next president with a multitude of crises.

But where there is crisis, there is opportunity. The leading Democratic candidates for president share positions that were considered political suicide as recently as 2004, and topics once shunted aside, like global warming, are of central importance. Withdrawal from Iraq is embraced by all the current candidates. Unfettered free trade is now viewed by most Democrats as an untenable position. Health care for all is a mainstream proposition. And it is not just these issues that have taken center stage but the core progressive values they represent: diplomacy over militarism, workers’ rights, the responsibility of government to see that social needs are met. Meanwhile, the Republican campaign has seemingly taken place in an alternate reality, with GOP candidates competing to win the title of Most Likely to Nuke Iran and Most Xenophobic.

The leading Democratic candidates share positions that were considered political suicide as recently as 2004.

With Democrats running left and Republicans slouching right, this election presents a historic opportunity to precipitate a progressive realignment. What is needed most now is not a candidate but a movement to surround that candidate, to brace his or her resolve, to press for the best platform and to hold him or her accountable.

Dennis Kucinich has been a forceful critic of the Bush administration, opposing the Patriot Act and spearheading the motion to impeach Vice President Dick Cheney. He is the only candidate to have voted against the Iraq War in 2003 and has voted against funding it since. Of all the serious candidates, only he and Gov. Bill Richardson of New Mexico propose a full and immediate withdrawal from Iraq. Only Kucinich’s plan sets aside funds for reparations. Moreover, Kucinich has used his presidential campaigns to champion issues like cutting the military budget and abolishing nuclear weapons; universal, single-payer health care; campaign finance reform; same-sex marriage and an end to the death penalty and the war on drugs.

But a Democratic mass movement has not coalesced around Kucinich’s run for president. In most cases, the rules of the Iowa caucus require that a candidate reach 15 percent of the vote to achieve “viability”; supporters of candidates who fail to do so can choose another candidate. Simply put, many Iowans soon will face a question that the rest of us may have to answer later: If not Kucinich, then who?

The leading Democratic contenders are Hillary Clinton, John Edwards and Barack Obama, and there are aspects of each candidate and campaign to be admired, and those that cause concern.

Clinton has proven herself a dedicated centrist, and when the center moves left, she has shown she can move, too. She has shifted from being an ardent supporter of NAFTA to calling for a “timeout” on all such deals. Clinton may not have apologized for her vote for the Iraq War, but she has called for its end. Her plan would begin slowly and involve retaining a “reduced residual force,” perhaps as many as 60,000 soldiers, to combat terrorism and train Iraqi military forces. As she indicated by voting for the Kyl-Lieberman amendment–which classified the Iranian Revolutionary Guards as a terrorist organization–her shift on Iraq did not reflect a fundamental political reorientation. Indeed, a Clinton administration could see a revival of her husband’s advisers and their pro-corporate, neoliberal policies. Certainly the presence of familiar and high-priced pollsters and lobbyists in the upper echelons of her campaign, as advisers and donors, is worrisome. Clinton’s election would represent a historic breakthrough for women, but there’s little reason to believe it would make ample space for a progressive agenda.

In contrast, Obama and Edwards are reaching for new ground. Each also presents the risks–and promises–of unknown potential.

On the campaign trail, Edwards has displayed a smart, necessary partisanship, denouncing corporate power and its crippling influence on government. He has argued that government does best when it does more for its citizens. He has not managed to consolidate the traditional Democratic base, and while he has loyal supporters among organized labor, he has not sewn up union support, nor has he excited a cohort of previously disenfranchised voters.

He has called for an end to poverty in 30 years, universal health care, a hike in the minimum wage to $9.50 by 2012 and an 80 percent reduction in greenhouse gas emissions by 2050, accomplished in part by creation of a green-collar jobs corps. His policy proposals are detailed and crafted in conjunction with progressive organizations. Most important, his programs were announced first, and they clearly pushed Clinton and Obama in a progressive direction. His health-care plan stops short of a single-payer program, but includes employer mandates and tax increases. Although he voted for the Iraq War and his plan to end it doesn’t commit to full and immediate withdrawal, he has repudiated that vote and proposes a faster pullout than his two main rivals.

Many have attributed a talismanic power to the personage of Obama–his mixed race heritage; the circumstances of his birth and childhood; his middle name, Hussein, often discussed as if it were in and of itself a foreign policy. But beneath the surface of symbols is a politician who was not only born different but who made different choices from other Beltway-bound Ivy Leaguers, especially in his early career as a community organizer on the South Side of Chicago.

Of the leading contenders, Obama shows the most potential to energize disaffected voters. He has campaigned for himself and others in states long written off by the Democratic establishment, and when he appears on the trail it is often alongside grassroots organizers and ordinary citizens. His team of advisers includes familiar former Clinton staffers but also experts plucked from academe and activism.

An Obama presidency would contain fresh faces, but would it have fresh ideas? His health-care plan is virtually identical to Clinton’s, except it does not include mandates, a conservative feature he curiously emphasizes. Likewise, his plan to exit Iraq exhibits the “strategic drift” toward leaving behind a significant residual force, as if fewer troops could accomplish what more have failed to do. Like Clinton, once in the Senate he has continued to vote to fund the war. These last two matters are especially unfortunate because they undermine what ought to be one of his greatest assets: Obama opposed the Iraq War from the beginning.

Since then his good judgment has seen some praiseworthy reprises – as when he bucked conventional wisdom by insisting on face-to-face negotiations with Iran, Cuba and Syria – but it often has tilted toward caution and centrism. Obama has cultivated the image of a post-partisan leader, one with enormous appeal to broad swaths of voters alienated from politics as usual. But if he governs that way, how will progressives who want to take on entrenched interests fare in his administration?

The Nation hopes that a progressive insurgency will make its influence more deeply felt. The front-loaded primary schedule, with individual states elbowing one another into the first days of 2008, could dampen that hope. It’s possible the election will be over in the blink of an eye, before progressives have had a chance to gather momentum. No matter which candidate is chosen, progressives will have to build the public support vital not simply for winning the election but for capturing the opportunity to transform the country.