Mark Schmitt wrote for Vox about how the two-party system does not help represent the diverse views of U.S. citizens:
Perhaps the most surprising result in presidential polls since the conventions is that more than one in 10 voters say they would support candidates not named Donald Trump or Hillary Clinton: Libertarian Gary Johnson and Jill Stein of the Green Party. In the New York Times/CBS poll released September 15, those candidates' combined 12 percent share was boosted by support for Johnson from more than a quarter of voters ages 18 to 29.
In real elections, neither of those two parties has ever come close to the level of support these polls indicate: Libertarians peaked at about 1 percent in 1980 (with David Koch on the ticket) and again in Johnson's previous run in 2012. Running as a Green, Ralph Nader — one of the country's "most admired" people for decades — captured 2.74 percent in 2000, just enough to swing that election to George W. Bush.