Independent presidential candidate Ralph Nader's support plummeted from four years ago, as returns early today showed him with less than half a percent of the national vote and unlikely to repeat his 2000 role as a villain to Democrats.

As the votes were counted, the consumer advocate delivered a broadside against those who worked to keep him off of the ballot in many key states.

"To the Democrats who spent millions of dollars and hundreds of lawyers and paralegals and harassers and intimidators going right to the homes of our signature gatherers, threatening them with jail, spreading lies about who was allegedly supporting us, I say the following," Nader told several hundred supporters gathered at the National Press Club last night. "Just stay tuned. We are just beginning to fight."

It was an end emblematic of a campaign that even Nader supporters acknowledge was more about advancing issues neglected by the two main parties and standing up for an independent candidate's right to run than about winning the White House.

Nader had long maintained that Democrats were exaggerating his potential impact on the race. Four years ago, he earned about 2.8 million votes nationwide but was accused by Democrats of swinging Florida and New Hampshire -- and therefore the election -- to George W. Bush.

This time, Nader, 70, who voted absentee in Greenwich, Conn., led Libertarian candidate Michael Badnarik by about 32,000 votes, according to the nationwide tally after midnight. In Florida, Nader earned more than 97,000 votes, or 2 percent, in 2000 -- when Bush won by 537 votes. With 99 percent of precincts reporting, Nader had 31,406 this year.

After spending recent months fighting lawsuits in states in which President Bush and Democrat John F. Kerry were competing closely, Nader ended up on the ballot in 34 states and the District, 10 fewer states than four years ago. Widespread fraud derailed one of his highest-profile drives, in Pennsylvania, where an analysis of his petitions turned up the names of celebrities and cartoon characters.

His organization consisted mostly of student volunteers because he lacked the resources to hire staff in most states or to conduct polls.

He also failed to earn the endorsement of the Green Party, which had backed him in two previous elections, and suffered the defection of a number of former backers, such as filmmaker Michael Moore and former running mate Winona LaDuke. He was later nominated by the Reform Party USA, a struggling organization that retains ballot lines in seven states.

Liberals, who had made up his core constituency, turned against him in droves, fearing he would again tilt the election toward Bush.

Nader, whose campaign focused on opposition to the Iraq war and on the influence of large corporations on politics, said his campaign was a worthwhile endeavor, despite the diminished support.

"As Eugene Debs once said and as I.F. Stone once said, the only struggles for social justice worth fighting for are those where you lose and you lose and you lose until you win," he said.

Walter J. Stone, who chairs the political science department at the University of California at Davis and is writing a book on third-party politics, said that unlike in 2000, Nader suffered this year because the electorate sensed important differences between the two major-party candidates.

"Third-party candidates depend on the feeling that the Democrats and Republicans are standing for the same things," Stone said. "That case couldn't be made as effectively this year."

In an interview after his remarks, the man who vaulted into the public consciousness in 1965 with the publication of "Unsafe at Any Speed," a book that led to passage of automobile safety laws, would not rule out another presidential run.

"All I know now is we're going to continue to mount an assault on this whole electoral mess," he said.

Ralph Nader lashed out at Democrats.