Ralph Nader, knocked off the presidential ballot in a series of states recently, lashed out against the Democratic Party on Thursday and accused its members of using intimidation tactics to prevent or dissuade people from signing petitions on his behalf.

The Green Party-turned-independent candidate said the Democrats are practicing "political bigotry," comparing the requirements that have kept him from appearing on some ballots to Jim Crow laws--segregation-era mandates that, among other things, prevented blacks in the U.S. from voting.

Petition signatures collected by supporters have been closely scrutinized and challenged by the Democratic National Committee, which has tried to keep Nader off the ballot on the basis of technicalities and "micro-provisions," Nader said.

"The whole process stinks, what we have to go through," he said, adding that fighting petition discrepancies in court is draining his campaign fund.