LAS VEGAS – The folks who gathered here this weekend for the first ever YearlyKos conference (named after the popular liberal Web site, Daily Kos) had better hope a Democrat does not win the White House in 2008.

Nothing smothers a growing movement of the politically disaffected quicker than premature victory.

In fact, the eponymous Kos – also known as Markos Moulitsas – could even be found doing a bit of ultra premature damage control on the conference’s last day.

At a panel on “Building Progressive Infrastructure” on Saturday, he laid out a time-frame for how long it would take the left to replicate the roughly 50 years of movement-building that conservatives have done – the founding of think tanks, cultivating of media outlets, and perfection of voter mobilization machines, etc.

“It took Republicans 30 years, right?” Mr. Moulitsas said, counting the years from the resounding loss of conservative presidential candidate Barry Goldwater in 1964 to the GOP takeover of Congress in 1994. “It won’t take us that long … we’re not out in the wilderness,” he said. Even with the Republicans having a massive infrastructure advantage, “they’re still only beating us by inches.”

“It’ll take us 10…. 2016 is when we’re going to be able to compete eye to eye,” he concluded. And then he added a warning: “Even if we do it in November, it’s not because the pendulum swung back, it’s because [the Republicans] really stunk it up.”

And therein lies the Kossacks’ greatest dilemma: the extent to which the strength of their movement is driven by a feeling of political impotence and rage at the current administration.

One gentleman I spoke to at YearlyKos was J. R. Jenks, a small businessman from Chicago. He drove out to the conference with his wife in their Prius. The top issue that drove him to hybrid it half way across the country, he said, was “how to set things back on track.”

“I’m a pacifist and a vegetarian,” he said, but even he is concerned about “what’s happened to our military.” He’s worried that we’re spread too thin to protect ourselves.

Another activist at the conference, going only by the screen name Navajo, came out to set up a “make your own tinfoil hat” stand.

The idea arose last June when she held a tinfoil hat contest for a 200-strong group of San Francisco area Kossacks that she’s organized back home. The idea is frivolous and ludicrous, no doubt. But it’s also fun – the kind of fun that a movement needs to be to keep its various members engaged and involved. How many activists, bloggers, and blog readers, it must be asked then, would be driving half way across the country, standing around making silly hats, and sitting around all day and night reading and writing blogs if, say, Nancy Pelosi, were speaker of the House and Hillary Clinton or Al Gore were president?

The 2008 Democratic candidates were out in force at YearlyKos. The Iowa governor, Tom Vilsack, was on a panel about education. The New Mexico governor, Bill Richardson, talked about energy policy and hosted a breakfast for bloggers. General Wesley Clark was on a panel about science. And a former Virginia governor, Mark Warner, was given a prime speaking spot at lunch on Saturday, the only one of the four presidential hopefuls to address the entire Kos crowd.

The momentum is currently toward national Democrats, led by Howard Dean, taking the net-roots seriously – not just as a source of potential contributions, but as foot soldiers and power brokers whose rings must kissed. But a victory too soon by a Democrat, especially the wrong Democrat, could spell disaster.

In the world of YearlyKos, a centrist Democrat is worse than Halliburton. If the “hated Democratic establishment” were reaffirmed in its belief that a moderated message is the path to victory, then the far left Kossacks would be left out in the cold.

If one won, the folks over at Daily Kos would be left with little to rage against, but nothing much to cheer either. And that’s no way to gas up the progressive Prius.

Mr. Sager is author of “The Elephant in the Room: Evangelicals, Libertarians, and the Battle to Control the Republican Party,” forthcoming from Wiley.