Gary Johnson, the Republican-turned-Libertarian Party presidential candidate, won’t come close to matching the vote totals of President Obama and Mitt Romney next month. Nonetheless, he's a variable in a handful of battleground states that could determine the outcome of the election.

Libertarian Party presidential nominee Gary Johnson spoke with The Washington Post's Brook Silva-Braga and responds to five key debate questions.

Presidential swing states with libertarian and independent streaks like Colorado, Nevada and New Hampshire are where Johnson threatens to be the biggest factor (Johnson's home state of New Mexico appears to be leaning towards Obama). And his presence on the ballot appears to imperil Romney’s support more than Obama’s. Conservative voters who are only lukewarm about the Republican candidate might be tempted to instead cast their vote for Johnson. Because of his social views, he could also steal some support away from Obama on the left, too, though perhaps not as much.

Still, Johnson’s overall impact could be very marginal on Nov. 6. He would only matter to Obama and Romney in states that are extremely close. Even the modest, single-digit support levels Johnson has been registering in polling may be overstated. Data from Gallup reveal that in recent elections, third-party candidates tended to poll better with a few months left in the campaign season than they actually perform on Election Day.

Johnson, a businessman who built a successful construction company, is no stranger to politics. He was elected governor of New Mexico in 1994, and reelected in 1998. He waged a campaign for the Republican presidential nomination last year, but after gaining little traction in a crowded field, Johnson opted to seek the Libertarian nomination late in 2011. He secured the party’s nod in May.

“I wouldn’t be doing this if I didn’t think I could do a really good job as president of the United States. And that is based on my resume, which is that I have been an entrepreneur my entire life and that I’ve been a two-term governor of New Mexico,” Johnson told The Washington Post earlier this month.

Like third-party candidates before him, many of Johnson’s policy positions are distinctly out of step with the major party contenders. He wants to legalize marijuana, abolish the IRS, and at a time when Obama and Romney are wrangling over who is the better protector of Medicare, Johnson is advocating for “raging debate” about cuts to the health-care program for seniors.

Johnson also embraces dramatic changes to the nation’s tax system. He wants to get rid of income taxes and corporate taxes and replace both with a “fair tax” on expenditures.

The former governor's economic platform has won him the support of some fiscal conservatives, and his social positions have helped him shore up support with others. His position on drugs has earned him praise from reform advocates, and his belief that gay couples should have the right to marry has caught the attention of same-sex marriage proponents.

While Johnson inspires passionate support among some voters, he’s yet to broaden his reach beyond a very small portion of the electorate. For some, that’s been disappointing.

Chris Barron, a co-founder of GOProud, a conservative gay rights organization, endorsed Johnson last year, but recently announced that he’s decided to vote for Romney. Barron's decision was rooted in pragmatism; he realized Johnson wouldn’t win, and decided that Romney would be a better choice than Obama.

The fact that Johnson’s campaign hasn’t caught on more with the public is a “missed opportunity,” Barron said in an interview, arguing that Johnson’s brand of fiscal conservatism and tolerant social views put him in line with "a vast swath of the American public,” and his credentials as two-term governor make him a more credible emissary than most third-party candidates.

Johnson hasn’t become the major factor supporters would have liked to see, but he isn’t going entirely unnoticed. Some Republican strategists fearful that Johnson would peel away support from Romney in some key battleground states tried to keep him off the ballot. Despite the resistance, Johnson has managed to get himself on the ballot in all but two states.

Johnson is not just competing against Romney and Obama. There are other candidates for president fighting to make their voices heard. Next Tuesday, they square off on the issues at a third-party debate sponsored by Free and Equal Elections Foundation. Longtime radio and TV host Larry King will moderate, and in addition to Johnson, Green Party candidate Jill Stein, Constitution Party candidate Virgil Goode, and Justice Party candidate Rocky Anderson will take part.

Whether Johnson goes down as a mere footnote when the history of the 2012 election is written remains to be seen. But for now at least, he’s another question mark in a campaign chock-full of uncertainties.