(CNN) - His name causes shivers in many Democratic circles, but Ralph Nader said Thursday his campaign history won't prevent him from another foray into national politics.
Nader, a persona non grata to many Democrats after he ran as a third-party candidate against Al Gore and George W. Bush in 2000, explained on CNN why he was recruiting potential candidates to run against Pres. Barack Obama in a Democratic primary.
"It isn't meant to defeat him," Nader said. "It is meant to hold his feet to the fire so he doesn't run around the country on Air Force One responding to the crazed Republicans, so he talks about the major issues that the majority of people care about."
Nader said his slate of challengers isn't meant to actually defeat Obama, but rather to provoke discussion among progressives about core issues.
"There are only about 20 primaries and it will be over quickly," Nader said. "Start in Iowa, to go New Hampshire. Do a number of primaries. There's an old saying. What is not discussed will not be advanced."
Nader also voiced support for the positions of one potential Republican candidate – former Alaska Gov. Sarah Palin.
"There isn't anyone else in the Republican primary, with the possible exception of Ron Paul, who is talking about big business controlling our political economy and our government in Washington. And she ought to be commended for that," Nader said of Palin.
Nader's primary challenge plan is already getting pushback from some prominent Democrats. CNN contributor and Democratic strategist Donna Brazile wrote in a CNN column this week that a Democratic challenge to Obama would be devastating for the party.
"A primary challenge could further divide the party and possibly dampen Democratic enthusiasm," Brazile wrote. "These races could erode our ability to reach swing voters, who are crucial to electoral viability, by forcing candidates to draw a sharper contrast on issues than necessary to win an election. On most issues, Nader agrees with the Democrats more than the Republicans."