WASHINGTON--Consumer rights activist Ralph Nader, accused by many Democrats of handing the 2000 election to Republican George W. Bush, said Sunday he was running again in this year's White House race.

"I'm running for president," he said on the NBC program "Meet the Press," while denying he was playing a spoiler role in the hard-fought campaign.

If the Democrats cannot win by a "landslide" this year, he said, "they should just close down."

But Nader, who turns 74 on Wednesday, said he still had a message to offer for the environment, workplace safety and against corporate interests by running as an independent candidate.

Emerging Democratic frontrunner Barack Obama's "better instincts and his knowledge have been censored by himself," he said, citing the Illinois senator's support of the Israeli "destruction" of the Gaza Strip.

Republican heir apparent John McCain was meanwhile "the candidate for perpetual war," Nader said, calling for the impeachment of the "criminal recividist regime of George Bush and (Vice President) Dick Cheney."

Standing as a Green party candidate in 2000, Nader took some 97,000 votes in Florida, triggering outrage among Democrats who believed he had siphoned off support from former vice president Al Gore and delivered victory to Bush.

But he won just 0.3 percent of the national vote as an independent in 2004, when he appeared on the presidential ballot in only 34 states.