Nader, who garnered nearly 3 percent of the national vote in the last presidential election, has not ruled out running for president as an independent and plans to make a decision by January.
"I think we're all a little bit disappointed," said Scott McLarty, a Green Party spokesman. "I suspect Mr. Nader would have gotten the nomination."
Several people have already declared their intentions to be the party's nominee, including Green Party general counsel David Cobb. Peter Camejo, the party's candidate in the California recall election, may also declare, McLarty said, adding that a front-runner will likely emerge before the party's convention in Milwaukee in June.
Nader stumped for Camejo in California and has also mentioned him as a possible Green candidate.
A consumer activist who became a household name decades ago for his efforts to push the auto industry to improve safety standards, Nader appeared on many Democrats' hate list after the 2000 election. Gore lost decisive Florida by fewer than 600 votes, while Nader got nearly 100,000 there. Many Democrats are convinced enough of those voters would have swung the election to Gore if Nader had not been on the ballot.
Nader and the Green Party rebuff such criticism, blaming a biased Supreme Court decision, the Florida Republican Party and Gore himself for running a weak campaign.
In an effort to gauge support, Nader has a new Web site and an exploratory committee, attends small fund-raisers, and has mailed letters to supporters. He said he has raised more than $100,000, mostly to pay expenses for the exploratory network, but is noncommittal on whether the resources are sufficient yet to persuade him to run.
"We're awaiting the feedback on resources and volunteers," he said in an interview Monday.
Nader said running as an independent would not hurt his campaign. "As an independent, you can do more innovative things because you don't have to check with all the bases," he said.
But McLarty said Tuesday it would be hard for Nader to get his name on the ballot in all states.
"He doesn't have the infrastructure to do that," he said.
The Green Party is debating whether to take a nominee on a full state-by-state campaign or to adopt a "safe state" strategy. Under that method, the party would mostly avoid states up for grabs, in order not to jeopardize the Democratic candidate's chances against President Bush.