LIANE HANSEN, host: And with the presidential election just 10 months away, NPR senior news analyst Daniel Schorr says, once again, the specter of a third party and the fear of a spoiler are beginning to loom over the campaign.</s>DANIEL SCHORR: Last Monday, in Norman, Oklahoma. Former senators David Boren and Sam Nun assembled a group of 17, mostly former senators and officials of both parties, to launch a campaign for bipartisan unity. They stressed the urgency of working together to address issues from health care to global warming. They proposed a creation of a unity government, including members from both parties, and they demanded a pledge of bipartisanship from the candidates in the current presidential campaign.</s>DANIEL SCHORR: How do they plan to enforce their demands? Well, one on this group is New York mayor and billionaire Michael Bloomberg. And that brings up the question of whether Bloomberg will enter the presidential campaign as a third-party candidate. Even to raise that idea is to send shudders through both parties. The most recent third-party candidate was Ralph Nader in 2000, who may well have caused Al Gore to lose the election.</s>DANIEL SCHORR: History reminds us of other independent candidates turned spoilers by their foes - the Dixiecrat Strom Thurmond, who failed to unseat President Truman in 1948; the same with former Alabama governor George Wallace, who took votes away from Richard Nixon and Hubert Humphrey in 1968 - Nixon narrowly won anyway. And then there was Ross Perot in 1996. He took 8.5 percent of the vote at the expense of both Bill Clinton and Bob Dole, but that didn't alter the outcome.</s>DANIEL SCHORR: And now, how about Bloomberg, who is joining this group of unity advocates, acting like a potential third force? He keeps denying that he's a candidate, but the possibility that he might run serves as a form of pressure on the current campaign. Boren says deadpan that Bloomberg is a good American and would not close the door to running if he thought it was his duty. Candidates, take heed.</s>DANIEL SCHORR: This is Daniel Schorr.
NPR Senior News Analyst Daniel Schorr says the possibility of New York Mayor Michael Bloomberg running as a third-party candidate for the presidency is sending shudders through both parties.