SYNOPSIS:

"The Republicans know the America they want, and they are not afraid to use any means to get there," Howard Dean said in accepting the chairmanship of the Democratic National Committee. "But there is something that this administration and the Republican Party are very afraid of. It is that we may actually begin fighting for what we believe."

Those words tell us what the selection of Mr. Dean means. It doesn't represent a turn to the left: Mr. Dean is squarely in the center of his party on issues like health care and national defense. Instead, Mr. Dean's political rejuvenation reflects the new ascendancy within the party of fighting moderates, the Democrats who believe that they must defend their principles aggressively against the right-wing radicals who have taken over Congress and the White House.

It was always absurd to call Mr. Dean a left-winger. Just ask the real left-wingers. During his presidential campaign, an article in the muckraking newsletter CounterPunch denounced him as a "Clintonesque Republicrat," someone who, as governor, tried "to balance the budget, even though Vermont is a state in which a balanced budget is not required."

Even on Iraq, many moderates, including moderate Republicans, quietly shared Mr. Dean's misgivings - which have been fully vindicated - about the march to war.

But Mr. Dean, of course, wasn't quiet. He frankly questioned the Bush administration's motives and honesty at a time when most Democrats believed that the prudent thing was to play along with the war party.

We'll never know whether Democrats would have done better over the past four years if they had taken a stronger stand against the right. But it's clear that the time for that sort of caution is past.

For one thing, there's no more room for illusions. In 2001 it was possible for some Democrats to convince themselves that President Bush's tax cuts were consistent with an agenda that was only moderately conservative. In 2002 it was possible for some Democrats to convince themselves that the push for war with Iraq was really about eliminating weapons of mass destruction.

But in 2005 it takes an act of willful blindness not to see that the Bush plan for Social Security is intended, in essence, to dismantle the most important achievement of the New Deal. The Republicans themselves say so: the push for privatization is following the playbook laid out in a 1983 Cato Journal article titled "A 'Leninist' Strategy," and in a White House memo declaring that "for the first time in six decades, the Social Security battle is one we can win - and in doing so, we can help transform the political and philosophical landscape of the country."

By refusing to be bullied into false bipartisanship on Social Security, Democrats have already scored a significant tactical victory. Just two months ago, TV pundits were ridiculing Harry Reid, the Senate minority leader, for denying that Social Security faces a crisis, and for rejecting outright the idea of diverting payroll taxes into private accounts. But now the Bush administration itself has dropped the crisis language, and admitted that private accounts would do nothing to improve the system's finances.

By standing firm against Mr. Bush's attempt to stampede the country into dismantling its most important social insurance program, Democrats like Mr. Reid, Nancy Pelosi, Dick Durbin and Barbara Boxer have, at a minimum, broken the administration's momentum, and quite possibly doomed its plan. The more time the news media spend examining the details of privatization, the worse it looks. And those Democrats have also given their party a demonstration of what it means to be an effective opposition.

In fact, by taking on Social Security, Mr. Bush gave the Democrats a chance to remember what they stand for, and why. Here's my favorite version, from another fighting moderate, Eliot Spitzer: "As President Bush embraces the ownership society and tries to claim that he is the one that is making it possible for the middle class to succeed and save and invest - well, I say to myself, no, that's not right; it is the Democratic Party historically that created the middle class."

For a while, Mr. Dean will be the public face of the Democrats, and the Republicans will try to portray him as the leftist he isn't. But Deanism isn't about turning to the left: it's about making a stand.

Originally published in The New York Times, 2.15.05