In the history of capitalism has any company had more success with just a wink and a nod than the Fox News Channel? And can Democrats be successful in the 2008 campaign by refusing to wink or nod back?

Last week's decision by Nevada Democrats, under pressure from liberal activists, to drop Fox as the co-sponsor of a party presidential debate has the virtue of crystallizing the questions about the network's nature and its unique role in the modern media ecosystem.

Fox cloaks itself in the mantle of objectivity with the nudge-nudge insistence that it—and it alone—provides "fair and balanced" coverage of the news. Then it advances its financial and ideological interests by promoting lurid accusations from conservatives against Democrats, accusations that are routinely debunked later by the mainstream media. Many Fox reporters are fair. But overall the network—through its language, its news decisions and its hosts—generally functions more like a cog in the Republican message machine than as a conventional news organization that attempts to abide, however imperfectly, by the traditional standards of (yes) fairness and balance.

Fox's possible participation in the Nevada debate, one of several the state party is sponsoring before next January's presidential caucus, presented Democrats with a conundrum that may become increasingly common for both sides as they navigate a media landscape in which overtly partisan sources of information are proliferating.

Democrats, with justification, consider Fox tilted against them. Yet the network has a large audience, at least some of whom may be open to Democratic arguments (though exactly how many remains subject to spirited dispute). The question the party faced was whether access to Fox's viewers was worth the validation the network would receive from hosting a Democratic debate.

Initially, the Nevada Democratic leaders answered yes. Party officials said they had no illusions about Fox's bent, but believed that airing the debate on the channel (as well as some of its broadcast affiliates in major Western cities such as Las Vegas) would allow Democrats to make a direct case to swing voters. And Democrats will need those voters to flip Nevada and other western states from red to blue in 2008.

"It may have been more of a general-election-type thinking than caucus-type thinking to go on Fox," said one advisor to the Nevada party. "But it made a lot of sense to try and reach out to people who aren't hearing from Democrats."

There's merit in that argument: No party can survive by talking only to people who agree with it. But Fox critics, led by the liberal advocacy group MoveOn.org, insisted the price for that access was too high and argued that it was self-destructive for Democrats to legitimize Fox in any way.

That argument struck a much more powerful chord than the Nevada Democrats expected, not only with the compulsive petition-signers online, but also with pillars of the Democratic political establishment. Many Democratic professionals believe that Fox will continue to provide an uncritical platform for almost any charge the right can dredge (Drudge?) up against the 2008 Democratic contenders.

Mark Mellman, the pollster for Kerry in 2004, passionately supported the decision to cancel the debate. "Everything Fox does is directed toward aiding and abetting the Republican Party, and it uses its newsgathering organization more or less as a cover for that," he said.

A senior advisor to one of the 2008 Democratic contenders was equally emphatic. "I think the more they can be de-legitimized the better," the advisor said. "They are in business to promote the Republican Party and to hurt the Democratic Party, and they have every right to do that, but to the extent that their pretense of objectivity can be challenged, it should be."

Even after this skirmish, Democrats are unlikely to completely ostracize Fox. John Edwards, who was the first to withdraw from the Nevada debate, said this week he wouldn't preclude future appearances on the network. And insiders say that despite another online uproar, the Congressional Black Caucus intends next week to announce plans to co-sponsor a Democratic presidential debate with Fox, just as it did in 2004.

But with this precedent established, Democratic leaders may increasingly view the network less as a megaphone than as a foil: They may try to demonstrate their toughness to their own activists by appearing on Fox to denounce it, the way Bill Clinton did in his finger-wagging encounter with Chris Wallace on Fox News Sunday last September.

As Democrats rethink their relationship with Fox, they may, in fact, be taking a lesson from the way conservatives deal with mainstream media organizations they consider biased against them, from big newspapers (like this one) to NPR and CNN (where I appear as a political analyst.)

The situation isn't exactly parallel. For all the howling on the right, it's difficult to argue that mainstream news organizations operate with anything approaching Fox' partisan and ideological agenda. (E-mails: commence now.) But there's no question many conservatives feel as wronged by elements of the mainstream media as Democrats do by Fox.

Conservative leaders and groups harvest those emotions to raise money and energize their supporters. And yet, when conservatives perceive it in their interest, they do not hesitate to deliver their message through those traditional channels. They are entirely comfortable throwing rocks at the big media institutions and then stepping through the broken glass to dispense a sound bite—or, for that matter, to dish dirt over cocktails.

That's the equilibrium Democrats are likely to reach with Fox: cooperation mixed with confrontation, guided always by self-interest. As a result, one of the premier conservative media institutions now faces the likelihood of a sustained siege from Democrats using the same fluid tactics many conservatives have long applied against the mainstream press. Fox executives might not consider such an outcome fair, but even they might have to concede that it is balanced.

Ronald Brownstein is the Times' national affairs columnist.