Ralph Nader was flanked by five supporters and two campaign aides at the Siam Orchid restaurant on Main Street. As usual, the fashion-unconscious candidate's coat pockets bulged, causing the flaps to hang open. He looked at the menu and asked, "What's the most innocuous combination of nutrients?"

"Mr. Nader, I'm Aaron Rizzio, and I'm your campaign coordinator in New Hampshire," one man said from across the table. Nader smiled. Rizzio asked whether the candidate was ready to address a meeting of his supporters.

"Where is it?" Nader asked.

"This is it," Rizzio replied.

Nader, 70, has every intention of playing a pivotal role in the 2004 presidential election, but his campaign is dogged by doubts, dissension and disorganization. The consumer activist is indefatigable, and his supporters are worshipful. But the pall of the 2000 election, in which many Democrats believe Nader tipped New Hampshire and Florida to George W. Bush, hangs heavily over the campaign.

In private, four of Nader's five supporters around the table said they will vote for Democrat John F. Kerry if polls in late October show Nader tipping the state to President Bush.

At Nader's previous campaign stop in a small conference room at Suffolk University in Boston, his top Massachusetts aide said he had tried to rent a larger meeting space at FleetCenter but was told the facility did not want to offend Democrats who were preparing to host their national convention there in July.

And at a California fundraiser, Nader said, two contributors were so fearful of the backlash from Democrats that they showed up in disguise.

"A lot of people get ostracized if they talk to us," Nader said in an interview at Cafe Luna on P Street in Washington, where he often meets reporters and conducts campaign business while his headquarters is being readied. At the California event, he said, "three people I've worked with for 25 years didn't come. These are people I've funded, groups I've started."

Nader still has some aces. Some Democrats find themselves lukewarm about Kerry and in greater agreement with Nader on issues. Nader has positioned himself as the "peace candidate": He wants to withdraw U.S. troops from Iraq within six months -- a position backed by neither Bush nor Kerry but endorsed by 40 percent of Americans.

A Gallup survey of registered voters last month found that Kerry led Bush 50 percent to 45 percent in 16 swing states; with Nader in the race, the Democrat and Republican were even.

Nader has been endorsed by the Reform Party, giving him ballot access in seven states, including Florida, where he won 97,488 votes in 2000 -- Bush's margin of victory there was 537 votes. A strong faction within the Green Party wants to nominate Nader at a convention Saturday night, and the likelihood of this was strengthened on Monday, when Nader chose longtime Green Party activist Peter Camejo as his running mate.

The Democrats are taking Nader seriously. This week, the Arizona Democratic Party joined an effort to block Nader from getting on the state ballot, and the Congressional Black Caucus heatedly asked him to drop out of the race.

On a recent Northeast campaign tour, Nader was hounded about whether he is helping Bush defeat Kerry. Nader stressed that he would draw more GOP voters than Democratic -- a stance belied by several polls, including a Washington Post-ABC poll in June.

In Boston, Nader was asked what Kerry could do to get him to quit. "Nothing," Nader replied. "This is not a game we are playing."

At Cafe Luna, Nader painted a picture of the Democrats' worst nightmare in late October polls: "Without me, Kerry is ahead. With me, he's behind by two points." Nader shook his head and said that would not prompt him to quit, even though he feels that Bush has been a disaster. "You never betray the people who sweated their hearts and minds for you," he said.

Democrats, many former admirers, accuse Nader of reckless egotism. He charges them with myopia. The "corporate paymasters" who are running the country are "not sweating" the 2004 election, Nader said, because Democrats do not offer a vision that is different from Bush's on getting out of Iraq, reducing military spending, raising the minimum wage and providing universal health insurance -- all of which Nader said ought to be core Democratic stands. Nader said the war in Iraq is "unconstitutional" and has called for Bush's impeachment.

In the Democratic primaries, only Rep. Dennis J. Kucinich (Ohio) shared his overall vision, he said, but Kucinich has been shut out by the party. "It's hard to run a cleanup campaign when you're inside a garbage can," Nader said.

But if Nader is certain about his course, the situation among his supporters is far more nuanced. New Hampshire provides a snapshot of the complexities roiling many battleground states. While Republicans tend to win most statewide elections here, conservatives often support centrist Democrats for president, said Andrew Smith, a professor of political science at the University of New Hampshire.

There is a strong libertarian streak in the "Live Free or Die" state -- made up of voters that Republicans, centrist Democrats and some Nader supporters such as Bill Grennon of Concord all believe are potential supporters.

Nader won 22,198 votes here four years ago -- three times the margin of Bush's victory over Al Gore. The loss cost Gore four votes in the electoral college, leaving him with 266; Bush won with 271.

While Nader insists he did not tip the state to Bush, Smith said that without Nader in the race, enough of his supporters would have probably voted Democratic to allow Gore to win. If things get worse in Iraq, Smith said, moderate Republicans may decide not to vote at all or cast a protest vote for Nader. Some Democrats who feel strongly about withdrawing U.S. troops from Iraq might abandon Kerry. But equally likely, Smith said, is that many who supported Nader in 2000 will vote Democratic. If Bush and Kerry "are within 2 to 3 percentage points, then a 3 to 4 percent Nader vote could be the difference," Smith said. "But the war would have to be going as bad or worse than it is now."

In the new Post-ABC poll, 55 percent of Kerry's supporters said they were casting votes against Bush, rather than for Kerry. Choosing Kerry, Nader repeatedly tells doubtful Democrats, is merely choosing the "least worst" candidate.

The dilemma for Kerry supporters was on display after Nader's visit to New Hampshire, when the state Democratic Party organized a teleconference with two Kerry voters who supported Nader in 2000.

"I agree with virtually every word he says," said Paul Twomey, 55, of Chichester, referring to Nader. But "we're heading over a waterfall, and we can't fight over who's in charge of the ship. What we're facing right now is a catastrophe."

By contrast, Greg Stott, 32, an eighth-grade teacher from Goshen, voted for Nader in 2000 and plans to do so again. The difference between voters such as Twomey and Stott is that the schoolteacher believes not only that Bush is bad, but that worse will come if the Democratic Party courts centrist voters at the expense of its liberal base. Nader says the United States is drifting so far to the right that "pretty soon the Republicans of today will be the liberal Democrats of tomorrow."

"Even if he doesn't win, I'm planting the seeds for my children," said Stott, who has volunteered to help collect signatures to get Nader on the New Hampshire ballot. "I want universal health care. I want the environment to be taken care of. . . . On Iraq, Kerry wants us to stay in Iraq. Bush does the same. Ralph wants us out."

Nader dismisses Democrats' criticism of him as a "spoiler." Groups that support the Democrats or the Republicans would instantly support third-party candidates if their core concerns were ignored, he said. "If both parties were against choice, how many seconds would it take [abortion rights groups] to form a third party?" he asked. "If both were for gun control, how long would it take the NRA to form a third party? These are core issues. We have 30 issues that are being shut out."

Among Nader's core issues are the 100 million Americans who do not vote because, he said, they perceive no difference between the Republicans and Democrats. Partly because of gerrymandering, he said, about 95 percent of congressional districts are not competitive -- by which Nader means they are nondemocratic. About 45 million Americans, he noted, do not have health insurance, and the minimum wage has long lagged behind inflation. Bush and Kerry could never take on corporate crime and military overspending because big corporations and the military-industrial complex fund their campaigns, Nader said.

Seen in this light, winning the election is not really the point. Nader's supporters are focused not on 2004, but on 2040. In Concord, one supporter compared him to Mahatma Gandhi. Nader declined the likeness, but he frequently says that real change -- revolution rather than reform -- comes from outside the two-party system. He cited the campaign to win women the vote, the civil rights struggle and the abolitionist movement.

Paradoxically, given Nader's themes, minorities do not appear in large numbers at his campaign meetings. In Boston, Nader drew about 70 people, but there was only one African American, Kenneth Thomas, who asked the consumer advocate why he draws so little support from the black community.

Nader replied that it is not for lack of trying. Over the years, he said, he has championed issues that directly affect minorities, such as a higher minimum wage, universal health insurance, crackdowns on predatory lending practices, and the recent problem of lead in the drinking water in Washington. African American churches are solidly Democratic, he said, and black voters are loyal to the Democratic Party because of its role in the civil rights movement.

Here in New Hampshire, Nader's critics said that -- despite the candidate's populist themes, grass-roots support and shoestring campaign -- he seems unable to empathize with the practical concerns of ordinary Americans worried about their country.

Chuck Grau of Bedford, who attended Nader's meeting here, said he is worried that Nader might help Bush get reelected, which would prolong the "quagmire" in Iraq and bring back the draft. Grau has a son in the eighth grade. "I think Ralph is unsafe at any speed," he said, in a reference to Nader's 1965 book about auto safety. "My son may get drafted because of him."

Assistant polling director Claudia Deane contributed to this report.

Ralph Nader has been endorsed by the Reform Party, allowing him access to seven states' ballots.Independent Ralph Nader, at a campaign stop in Connecticut, says, "A lot of people get ostracized if they talk to us."Nader contends that there is little separating the two main parties.