According to Slate, Ralph Nader, who took a sizeable portion of the electorate in 2000, will be running for President again:
The prospect of another Nader candidacy should surprise no one. (He ran again in 2004, after all.) But it's hard to see him taking a significant bite out of the Democratic vote this time around. In 2000, many Dems, disaffected with the Clinton White House, wanted to try a third way. In 2004, Kerry was so uninspiring that a Ficus tree could have launched a viable third party candidacy. But this year, Democrats are generally pleased with their options.