Lonely quest for 3rd party presidential hopefuls

That Goode's sign was there at all in this pivotal state served as a reminder that plucky third-party candidates like the Constitution Party's nominee could muck up the works on Election Day. Libertarian Party candidate Gary Johnson is daring unsatisfied voters to "waste" their vote on him in the 48 states where he's on the ballot.

"I hope to rain on the party. And by that I mean the two parties," Johnson, a former New Mexico governor, told The Associated Press on Saturday as he wrapped up his late swing through battleground Ohio after a college-town push in Colorado. "I hope to rain on it big time."

Some polls have shown Johnson and former Virginia Rep. Goode, two not-long-ago Republicans, as primed to pull down more votes than the difference between President Barack Obama and Romney in critical states such as Colorado, New Mexico, Ohio and Virginia. Experts caution, however, that the overall tightness of the race tends to work against third-party candidates in the end as voters migrate back to the main nominees.

In every presidential campaign, there is talk about a credible alternative emerging to seriously test the Democratic and Republican nominees. Aside from Texas billionaire Ross Perot's 1992 campaign, the phenomenon has seldom panned out in recent times. A much-hyped bid this year to field a bipartisan ticket this time fizzled when Americans Elect, a group that had secured ballot space around the country, retreated in May.

The aim among the 2012 hopefuls seems more about roiling the two-party system.

Johnson is running a late batch of TV ads and airing them during the cheaper off-hours in only a half-dozen states. They urge people to "Be the 5 percent" by getting him to that vote threshold.

"In 2012, do something revolutionary. Cast a protest vote that counts," Johnson says, flashing a peace sign and emphasizing his "Live Free" slogan at the ad's end. He's casting himself as more fiscally conservative than Romney but more socially liberal than Obama.