There are now two resistance movements that are winning. The first, of course, is the one in Iraq, which is gaining in its war against the U.S. occupation. And the second is the resistance movement inside the Democratic party, which is increasingly vocal in its demand for the United States to get out of Iraq.

Next week, the entire House Democratic caucus will meet in closed session with one item on the table: Iraq. Don’t expect the Democrats to come up with a unified position: Donkeys will fly before that happens. But to say that the meeting is crucial is an understatement, and it is likely to mark that start of a year-long battle that will pit the party’s progressives, now joined by Rep. John Murtha, against both nattering nabobs like Hillary Clinton and the ever-warlike Liebermansheviks.

According to a source on Capitol Hill, there isn’t a clear agenda for next week’s meeting, but it is a hopeful sign that Democrats might be finally be getting ready to speak clearly on Iraq. It’s unlikely, they say, that House Minority Leader Nancy Pelosi, who is now supporting Murtha’s courageous call for a six-month withdrawal timetable, will try to force a unified Democratic stand. But it’s guaranteed to be a lively discussion, one in which the various species of stay-the-course and sorta-stay-the-course Dems will be on the defensive. (Important historical note: By a majority of 126-81, House Democrats voted against the war in 2002, according to Roll Call , which first reported the meeting of the caucus next week.)

The caucus meeting itself was directly triggered by Murtha’s bombshell, which thrilled progressives and anti-war activists. It has given new momentum to the push by Reps. Lynn Woolsey and Neil Abercrombie, who’ve introduced a resolution that calls on the Bush administration to start withdrawing troops no later than next Halloween, and it has reenergized the House’s Out Of Iraq caucus. Abercrombie told me the organizers of the so-called Jones-Abercrombie resolution (the Jones being Rep. Walter Jones of North Carolina, the Republican version of Murtha) are willing to substitute Murtha’s far stronger, out-in-six-months resolution for theirs. And he said that they will begin organizing for a discharge petition to force a vote on it. Since such a petition requires a majority of the House, there’s no chance it will happen, but it provides the anti-war House Dems with a good organizing tool.

Naturally, the Liebermansheviks are in high dudgeon, warning that if the party decides to align itself with the vast majority of American voters, it will be a mistake. In today’s Washington Post , Marshall Wittman of the Democratic Leadership Council invokes the terrifying name of Rove the Mighty to scare the party away from doing the right thing. "If Karl Rove was writing the timing of this, he wouldn't have written it any differently, with the president of the United States expressing resolve and the Democratic leader offering surrender. For Republicans, this is manna from heaven," says Wittman. Why, exactly, Democrats ought to take advice from a former Christian Coalition leader who worked for uber-hawk John McCain isn’t exactly clear—never mind the fact that Rove may soon be indicted for lying or leaking state secrets in defense of the war. (The Washington Times and Rev. Moon are smiling, too, running a headline today that reads: "Democratic split on war thrills GOP." It quotes the spokesman for the Republican National Committee saying Pelosi et al. have adopted a "defeatist position of retreat" in Iraq.)

It isn’t often in politics that doing the right thing coincides with doing the thing that is politically popular. As I wrote last week in Rolling Stone , there are three elements to a new policy for Iraq: First, set a date for withdrawal; second, start negotiating with enemy, that is, with the non-Zarqawi resistance; and third, internationalize the effort. That latter step would involve an international mediator, the United Nations and the Arab League. It has the added, and comforting, benefit of making President Bush look like the weak, flailing, strategy-less executive that he is.

From a moral standpoint, packing up and leaving Iraq is the right thing. The war in Iraq has become a moral blot on America’s soul. U.S. troops in Iraq are dying to defend a Shiite theocracy allied to Iran that operates death squads, tortures prisoners with electric drills and fosters violent sectarianism. Meanwhile, in support of that anti-democratic gang, our forces are killing thousands of oppositionists to no useful result. And the war is being led by Bush administration officials who lied to start the war, who support torture of our enemies in secret prisons and who seem obsessed with what they see as a titanic struggle against an imaginary Evil Caliphate.

From a political standpoint, too, getting out of Iraq in 2006 is a winner. Since last summer, poll after poll has shown that something like two-thirds of Americans now believe that the war in Iraq wasn't worth fighting, and more than half say that the war in Iraq has not made the United States safer. More and more GOPers are having doubts about the war, and the looming election will concentrate their minds wonderfully. That’s what makes it all-important for the Democrats to define themselves by supporting Get the Heck Out. Not because it will cause the Republican caucus to splinter, which it will—why would Republicans want to go into 2006 with the Bush-Cheney war albatross tied to their necks? But because by doing so, they will guarantee that the war in Iraq ends in 2006.

Now, does that mean that the Democratic Party will embrace a Murtha-style stand? Sadly, no. The party has enough Liebermansheviks to guarantee it remains divided. Rep. Steny Hoyer of Maryland, that paragon of Middle East expertise, is doing his best to undermine his party’s majority. "I believe that a precipitous withdrawal of American forces in Iraq could lead to disaster, spawning a civil war, fostering a haven for terrorists and damaging our nation's security and credibility," he chirped. Despite Hoyer, though, the good guys are winning on this one.