WASHINGTON In Republican Mitt Romney's bid for the White House, there are the obvious obstacles: namely a sitting president, Democrat Barack Obama, and his massive campaign organization.
And then there are the less predictable hurdles - such as Gary Johnson, a self-effacing former New Mexico governor who could complicate Romney's efforts to challenge Obama in New Mexico, Colorado and Nevada in the November 6 election.
Johnson, 59, is the Libertarian Party's nominee for president and, by most measures, a fringe candidate. He wants to cut the U.S. government's budget by a whopping 43 percent and legalize marijuana, and he struggles to persuade pollsters to even include him in their surveys of voters.
In a campaign in which the two main contenders and their allies could raise nearly $1 billion each, Johnson has raised a little more than $800,000 through the end of April.
But Johnson, who left the Republican Party in December after his presidential bid could not get traction there, has entered the summer campaign season carrying just enough weight to be a factor in the fall.
He is likely to be on the ballot in all 50 states and has qualified to receive matching campaign funds from the U.S. government. Most significantly, he appears to be picking up enough support in the western United States to affect the battle between Obama and Romney - most likely in Obama's favor, according to analysts who say much of the support Johnson could get probably will come from potential Romney voters.
Like Texas Representative Ron Paul, Johnson is trying to tap into some voters' rising anxiety over a soaring U.S. government deficit and concerns that Washington has too much of a role in Americans' lives.
Johnson - who turned a plumbing and remodeling business into one of New Mexico's largest construction companies before selling it 1999 - rejects the notion that he could be a third-party spoiler for Romney, as Ralph Nader was to Democrat Al Gore in 2000 and Ross Perot to Republican George H.W. Bush in 1992.
He envisions a scenario in which his campaign will get a boost in September, after Paul - a Republican who also calls for an extremely limited government - is expected to leave the presidential race. Although Romney has clinched the Republican nomination, Paul remains in the race, which could give him a chance to influence the party's platform at its convention in Tampa, Florida, in late August.
Johnson, a marathon-runner, hopes to inherit Paul's small but devoted core of fans as the presidential race enters its final stretch.
"I can't imagine a Ron Paul supporter who is going to support Romney," Johnson said last week during a visit to Washington, adding that Romney envisions a larger government than Paul supporters favor.
ALTERING THE RACE
In the state-by-state race for the presidency, Romney's prospects would brighten considerably if he could win New Mexico, Nevada and Colorado, politically divided states that Obama won in the 2008 election.
Winning one of those states would reduce the pressure on Romney to win larger, hotly contested states such as Ohio and Virginia.
For Romney, it is a tall order. New Mexico, Nevada and Colorado have experienced significant growth in Latino voters and a decline in white, working-class voters in recent years, a trend that generally favors Obama.
By the election, Johnson's campaign could become a headache for Romney in those three states.
Nearly anonymous nationwide, Johnson is popular in his home state. A survey of New Mexico voters in May, taken by Patriot Majority USA, a Democratic group, found Johnson polling at 12 percent there, compared with Obama's 48 percent and Romney's 35 percent.
"The presence of Gary Johnson on the ballot significantly undercuts Romney's long-term viability" in New Mexico, said Craig Varoga of Patriot Majority.
Others say that Johnson's showing reflects an unhappiness with Obama and Romney, and that his support will shrink as election day approaches.
Nevada has been a nettlesome state for Romney's campaign.
With the state party divided between Romney and Paul supporters, Romney has created his own statewide team to carry out his campaign there. Last week, the Clark County Republican Party - which includes many Romney critics - erected a billboard in Las Vegas that compared Romney with George W. Bush (no compliment intended), and Paul to Ronald Reagan.
Johnson hopes that enthusiasm for Paul in Nevada will transfer to him.
His views have some appeal in Nevada. He would like to sell off federal lands, a perpetual gripe in a state where the federal government owns more than 80 percent of the land.
Johnson's stance that government should not impose moral values is suited to the gambling city of Las Vegas, which hosted last month's Libertarian Party convention where Johnson won the party's nomination for president.
"I don't think a lot of Republicans in the state are sold on Romney," said David Damore, a professor of political science at the University of Nevada, Las Vegas. "There's an opportunity for Johnson to siphon some votes here."
In Colorado, the birthplace of the Libertarian Party, Johnson may get an extra jolt at the polls for his steadfast support for easing restrictions on marijuana. In November, Coloradans will vote on a ballot initiative to legalize marijuana and regulate the drug like alcohol.
"Gary Johnson could land up having a surprisingly impressive showing in a state like Colorado," said Ethan Naddelmann, founder and executive director of the Drug Policy Alliance, which supports easing drug laws. "It's possible that the Libertarian vote could make the difference."
As in Nevada, there has not been a recent of survey of support for Johnson in Colorado. In May, the Democratic Public Policy Polling found 9 percent support for Johnson in neighboring Arizona. Johnson's campaign figures he would poll at similar levels in Colorado and Nevada today.
The trio of western states account for 20 electoral votes in the presidential election, a significant chunk in a tight race in which 270 electoral votes are needed to win the White House.
Polling aggregator Real Clear Politics estimates that Obama is likely to win 221 electoral votes, Romney is likely to win 170, and states representing a total of 147 electoral votes are toss-ups.
‘THE LONG HAUL'
The 2000 election vividly showed how a third-party candidate can affect a presidential election. Democrats still fume about the 97,488 votes that liberal Green Party candidate Nader received in Florida, a state that Republican George W. Bush won over Democrat Gore by 537 votes, thereby clinching the election.
Similarly, billionaire and independent candidate Perot undermined Republican President George H.W. Bush's re-election campaign in 1992 by winning 18.9 percent of the vote. Democrat Bill Clinton won that election.
The Libertarian Party has never made much of an impression on a presidential campaign. The high-water mark for the party was 1.1 percent of the vote, achieved in 1972.
In the last presidential campaign, former Georgia Representative Bob Barr topped the Libertarian ticket and received 523,000 votes. In Cook County, Illinois, alone, more than three times as many people turned out for Obama than did for Barr in the entire country.
Johnson does not sound daunted by the odds against him, or by the suggestion that at best, all he can hope for is to make things tougher for Romney in a few states.
He calls running for president "a bucket list item."
"I wouldn't be doing this if the country wasn't in deep doo-doo," he said.
His advisers say he already is planning another presidential run in 2016.
"Gary is an endurance athlete. He has competed in over 30 marathons and triathlons," said Ron Nielson, Johnson's political strategist since 1993. "He understands the concept of the long haul. You just keep going."
(Editing by David Lindsey and Mohammad Zargham)