And today, Barack Obama says it's clear now that Nader "did not know what he was talking about" when he said he hadn't found any differences between Gore and Bush back then.
Hillary Rodham Clinton says Nader's candidacy won't be helpful to this year's Democratic nominee -- but she adds, "It's a free country."
As for Nader, he says there's no chance that his entry into the race will tip the election to John McCain. He says Americans won't vote for a "pro-war" McCain.
And he tells NBC that if the Democrats can't win in a landslide this year, they should "wrap up, close down, emerge in a different form."