Continued from page 1

“In some ways, parties are like competitive businesses,” Mr. Kazin added. “Unless they grow, they’re going to be in deep, deep trouble, so they need to grow. That’s true of parties everywhere, but it’s especially true in the two-party system.”

Mr. Johnson, the Libertarian nominee, blames the media for his lack of traction.

“I polled at 6 percent in Ohio, but with all the talk about Ohio, do you hear my name six times every 46 times you hear Obama’s name? Absolutely not,” said Mr. Johnson, a former two-term Republican governor of New Mexico. “Man, it’s a real phenomenon that the deck is stacked against the third party.”

That third-party candidates go unnoticed by the press and rarely take more than a fraction of the vote, however, does not make them irrelevant.

To the contrary, said Henry Olsen, who heads the National Research Initiative at the American Enterprise Institute. “Fringe candidates can affect the outcome of an election.”

“They can be decisive in a lot of ways, often in ways that don’t necessarily show up in how well the candidates do, but rather where they do,” said Mr. Olsen, who suggested George W. Bush may not have become president in 2000 were it not for Green Party candidate Ralph Nader.

Mr. Nader was “inconsequential nationally, but because of our electoral system, he cost [Al] Gore Florida, and hence cost him the election,” Mr. Olsen said.