A Libertarian Party supporter campaigns for its presidential candidate, Gary Johnson. Photo published by Johnson's campaign on Flickr (CC licence). 
While it may seem that Barack Obama and Mitt Romney were the only two contenders in the US presidential election, there were actually quite a few more. Candidates from “third parties”, as smaller parties are called, perhaps had a better chance of seeing hell freeze over than winning the White House, but they and their voters were banking on the idea that the more votes they got, the more attention their ideas will get.
The biggest third party challenger in this year’s race was the Libertarian Party, led by Gary Johnson. Neither on the left nor the right, the Libertarian Party describes itself as socially tolerant and fiscally conservative, making it tempting for voters who were hesitating between the two major parties.
Then there’s the Green Party, which some worried could have split voters on the left. Many Democrats today still blame 2000 Green Party candidate Ralph Nader for taking decisive votes away from Democrat Al Gore in the swing state of Florida.
Candidates from these two parties, as well as candidates from the conservative Constitution Party and the left-leaning Justice Party, took part in a “third party” debate on Monday, which was given very little media coverage compared to the Obama-Romney debates.

“The major party candidates represent powerful capitalist interest that don’t align with my working-class preferences”

Bryan Emmel lives in Moorhead, Minnesota. He told us he planned to vote for Justice Party presidential candidate Rocky Anderson.
Minnesota isn’t considered a swing state, but I would be voting this way regardless. I consider myself a democratic socialist but ‘socialist’ is a dirty word in the United States. The Justice Party best articulates my beliefs.”
Both major party candidates represent powerful capitalist interests that do not align with my working-class preferences. We need guaranteed, universal health care and neither Obama nor Romney support that. Obama has been a huge promoter of war and killing and has led a crackdown on whistleblowers such as Bradley Manning in spite of his earlier promise to lead an open and honest administration. […] Romney, meanwhile, is just a traitor who doesn’t want to pay taxes in the United States. He is just a typical rich person who used deferments to dodge the Vietnam war but he expects the rest of us to send our children to be blown up and maimed so that the United States can secure natural resources that don’t belong to us.

“Both Obama and Romney have no allegiance to the US constitution”

Ronnie A. Jimenez lives in San Antonio, Texas. He told us he planned to vote for Libertarian Party candidate Gary Johnson.
At the beginning of the campaign, I rather passionately supported Ron Paul; however since he is no longer in the running, I have chosen to throw my support behind the candidate closest in beliefs. Both Obama and Romney are completely unacceptable candidates who have no allegiance to the US Constitution. In 2008, Obama campaigned against unconstitutional practices such as the Patriot Act, but since then has renewed it. He promised to end the war in Afghanistan but only increased our presence there, and now in a vain attempt to look like he is moving in that direction has replaced troops with contractors, further feeding the military-industrial complex. He promised to respect states’ rights and no longer waste resources on marijuana crackdowns, but has been even more aggressive than George W. Bush was. And the list goes on.
Now you may think Romney might be better, but no! Like Obama, he supports the National Defense Authorization Act. [Editor’s Note: The latest version of the act allows the military to indefinitely detain terrorism suspects without charge or trial].
I don’t live in a swing state, but I would vote for the Libertarian ticket under any circumstances at this point. It is an issue of principle for me – I am often lectured by fellow citizens who say I am throwing away my vote, or perhaps helping ‘the other guy’, but this is how change happens – you have to draw a line in the sand and not budge.

“I’m voting Green to support third parties in general – they’re badly needed to challenge the two main ones”

Dustin Smith lives in Houston, Texas. He told us he planned to vote for Green Party presidential candidate Jill Stein.
I'm voting for Stein because I support her entire platform, which includes single-payer healthcare, a 50% cut in military spending, and a detailed plan to increase workers' wages and rights. Another reason I'm voting for her is to support third parties in general: They're badly needed to challenge the two main ones, which over the years have become two versions of corporate-run conservatism, one centre-right, and one far-right.
I'm voting for Jill Stein with the aim that my vote will, when joined with other votes for Stein, gain some attention in Washington and, even if slightly, move policy to the left.
However, if I lived in a swing state, I would vote for Obama. While his platform is too conservative for me, it is different enough from Romney’s to drastically affect the lives of many people. From domestic issues such as healthcare to international ones such as dealing with Iran, it's easy to conclude that, to put it simply, less people would die under Obama than under Romney.