Give George W. Bush credit where credit is due: He has reversed the characteristic election-year dynamics of the two major parties.

With just five months to go before Election Day, the Republicans sound like a bunch of querulous Democrats. As my colleague E.J. Dionne noted in his Post column yesterday, a broad array of Republicans are loudly criticizing the president's Iraqi occupation policy for its lack of realism or idealism or both.

What's more surprising, though, is that Democrats are behaving in the kind of unified fashion associated with Republicans. Party factions that have defined themselves by opposing other party factions are now puffing peace pipes. And while many Democrats have been mumbling audibly about the failure of nominee-in-waiting John Kerry to define himself clearly, there's been remarkably little Democratic criticism of Kerry's position on Iraq.

This marks the suspension of every known law of Democratic thermodynamics. The party's rank-and-filers and an increasing number of its foreign policy elites favor setting a date for the withdrawal of U.S. forces from Iraq. Kerry, like Bush, favors an open-ended commitment, though he insists that there be a clearer international aegis for and participation in the Iraqi force. Kerry's position may change, of course, if the level of violence in Iraq increases or subsides, or if rifts emerge between the new Iraqi interim government and our force there. But for now the line between Kerry's policy and Bush's is a lot less clear than millions of Democrats would like it to be.

What's particularly ironic is that the current Democratic campaign cycle began with an almost consensual revulsion at the failure of the party to define itself more clearly against Bush in the 2002 midterm elections. Declining to wage a national campaign against either Bush's tax cut or his pending preemptive war, the Democratic leaders in both houses of Congress managed to depress Democratic turnout and lose Democratic seats. Reaction was swift. In primary states, Democrats started flocking to the banner of Howard Dean, who was running as much against his own party's timidity as the Republicans' recklessness. In the House, Democrats elected as their new leader Nancy Pelosi, who vowed never to let the party go into a campaign where it didn't "draw clear distinctions" between its policies and the GOP's.

Kerry, of course, has drawn strikingly clear distinctions between his policies and Bush's on economics, social tolerance and the role of America in the world -- just about everything, in fact, except the future of the Iraqi occupation. But in past campaigns, that would not have protected the Democratic standard-bearer from the brickbats of the faithful.

This year, however, is different. The antiwar coalition Win Without War is nonetheless a hotbed of Kerry supporters. And at the national conference of the liberal Campaign for America's Future beginning today in Washington, it's not likely that a lot of time will be devoted to criticizing Kerry's stance on Iraq, though it's certain that few attendees actually share his position. Unless and until liberals believe that Kerry's position will hurt him at the polls, most seem prepared to swallow their misgivings.

But then we are living through a springtime of Democratic harmony that is the direct result of the three-year winter of discontent Democrats have experienced under Bush. In the current (June) issue of the American Prospect (the liberal monthly for which I work as editor-at-large), for instance, co-editor Robert Kuttner jointly authors a piece with Will Marshall, president of the Progressive Policy Institute and longtime chieftain of the Democratic Leadership Council, that delineates points of agreement on economic policy between the party's left and center-right wings.

This doesn't mean that Kuttner (or I) has abandoned longstanding differences with the DLC over, say, trade policy. But the Kuttner-Marshall article -- the result of a series of meetings between DLC-niks and their historical adversaries from labor-liberal institutions around Washington -- does assert, rightly, that all wings of the Democratic Party are united in opposition to Bush's single-minded obsession with enriching the rich. It lays out a baseline for current Democratic economics, a formula for sharing prosperity more broadly whose tenets range from "pay-as-you-go" rules for tax cuts and spending to legislation making it easier for workers to join unions.

The Marshall-Kuttner manifesto is just one sign of a larger unity that the party has come to embrace this year, chiefly around the causes of a more populist economics, a more disciplined fiscal policy and a more prudent and heavily armed mutilateralism in foreign policy. It's not clear whether John Kerry's Iraq policy will continue to command the same unity. But for now most Democratic doves seem satisfied that Kerry would not have gotten us into this war, and are willing to play down criticism of his plan (what is it again?) to get us out.