This election is quite possibly the worst we have had in a long time. Trump and Hillary are like two school kids flexing their muscles in the middle of a game of show and tell, it is ridiculous. Gary Johnson seems like an honorable candidate who is tired of all the nonsense. If people really get behind him then maybe a third party candidate could win the presidency. I mean, a businessman turned reality TV star is now the Republican frontrunner so anything can happen in this day and age if we let it.
Gary Johnson is the face of a movement, a movement that has been around for a while though and has never made this much of an impact. That movement, of course is the libertarian movement. Libertarians believe in the simplest interpretation of the Constitution, and as such, need far LESS government to operate. That doesn't sit well with the establishment who continue to make the Libertarian Party a laughing stock.
I don't believe Gary Johnson has a chance to win the United States presidential election. The cost to run and win a presidential election is extremely high. A third party candidate is not going to receive the amount of money necessary to mount a strong campaign. If you don't have the money for advertising and staff to get your message out, it is very unlikely that you can win.
A third party candidate has virtually no chance of winning an election in the United States, largely because you can't win without the money and infrastructure offered by the two major parties. Thanks to the constitution, it is not likely that any third candidate will ever be successful, due to the way ties are broken.