The first barrier to a non-Democratic and non-Republican challenger is ballot access. The process by which third-party and independent candidates get on the ballot is determined by state law, and those laws vary widely from state to state. As a result, the only candidates who will be on the ballot in all 50 states and Washingon, DC are the Democratic and Republican nominees. This gives them a head start in the battle to win the 270 Electoral Votes needed to become president.
The second barrier is that all but two states allocate their Electoral Votes on a winner takes all basis. That means that whichever candidate has the most votes wins ALL the state’s electoral votes (except for Maine and Nebraska). To do so, a candidate needs to win only a plurality of votes in a state—one vote more than the second highest polling candidate—and not an outright majority. The more candidates are on the ballot, the easier this becomes, but that still favours the two dominant parties because have the most money to spend on promotion and get the most (well, all, actually…) of the mass-market news media’s attention. This is also why it makes no difference how high a third party candidate is polling nationally—all that matters is if they’re polling high enough in enough states to win enough states to get a total of 270 Electoral Votes, or if they can at least come in third, should no candidate reach 270. More about that later.
Third, with limited ballot access, the need to win more votes than any other party, and the tendency of the news media and voters alike to focus only on the two dominant parties, third parties and independent candidates have no chance.
Two third parties—the Green Party and the Libertarian Party—are courting Bernie Sanders’ supporters and the Libertarians are also courting disaffected Republicans. I’ll look at whether that’s realistic later, but right now, let’s look at the problems faced by those two parties, the biggest alternatives to the Republicans and Democrats.
Ballot access first: According to Wikipedia—which had the only comprehensive list I could find—neither the Green Party nor the Libertarian Party is in a position to win the election outright.
At the moment, the Green Party is on the ballot in Arizona, Arkansas, California, Colorado, Delaware, Washington D.C., Florida, Hawaii, Louisiana, Maine, Maryland, Massachusetts, Michigan, Mississippi, New Mexico, New York, Ohio, Oregon, South Carolina, Texas, West Virginia, Wisconsin (21 states and DC). Together, that adds up to 296 electoral votes out of 538. Since 270 is needed to win, that may look promising. However, look at that list again, and notice how many of those states the party stands zero chance of winning. In fact, in most of them they’re likely to get a tiny percentage of the popular vote, and in none of them will they be able to come ahead of both the Democratic and Republican parties—and the Libertarian Party.
In 2012, the Green Party was on the ballot in 38 states and DC, meaning that 83.1% of voters saw them on their ballots. Yet the party received only 0.36% of the popular vote nationwide, and was behind the Libertarian Party nearly everywhere. In sum, the Green Party wasn’t a threat to the two main parties—or even the Libertarian Party—in any state.
The Libertarian Party is in a better position—kind of. The party’s on the ballot in Alaska, Arizona, Arkansas, California, Colorado, Delaware, Florida, Georgia, Hawaii, Idaho, Indiana, Kansas, Louisiana, Maryland, Michigan, Mississippi, Missouri, Montana, Nebraska, Nevada, New Mexico, North Carolina, North Dakota, Oklahoma, Oregon, South Carolina, Texas, Utah, Vermont, Washington D.C., West Virginia, Wisconsin, Wyoming (32 states and DC). Together, that adds up to 335 electoral votes out of 538. However, their odds are no better than the Greens’.
In 2012, the party was on the ballot in 48 states and DC, and 95.1% of US voters saw the party on their ballots. Even so, the party still only managed 0.99% of the popular vote nationwide, an extremely distant third to the two main parties. In sum, the Libertarian Party also wasn’t a threat to the two main parties in any state.
This year, it seems likely that the nominees of the two minor parties will be the same as in 2012, not that most US voters would know that, of course. Still, with some Republicans in the “Never Trump” camp, and some of Sanders’ most fervent fans pledging “Bernie or bust”, could this be the year that a third party makes a difference?
Of course not.
As we’ve seen, the two largest third parties have been little more than footnotes. Some Republican voters may vote Libertarian, and some of Bernie’s may vote Green, but there are unlikely to be enough to make a difference in any state, and they’d need to win in many states to win the presidency. Time and time again, despite what they claim at the end of the nomination process, US voters divide up among the two main parties or staying home, and there’s nothing—yet—to indicate that this year will be any different.
Besides, apart from voting against the candidate who beat the party candidate they preferred to see nominated, what do the two main alternative parties offer to disaffected partisans? Not a lot.
In my view, only the Green Party is a logical fit for Bernie’s most fervent fans because it’s mostly leftist on both social and economic issues. The Libertarian Party, on the other hand, is conservative on economic issues and merely similar to liberals on some social issues, like marriage equality and abortion, but only because they think the government has no right to be involved (but private businesses can do and discriminate as they please, which liberals disagree with). Because Sanders’ entire campaign has been focused on economic issues, I simply cannot see his most fervent fans going for a candidate who’s far more conservative on economic issues, even if there could be a little overlap here and there.
For Republicans, it’s even more complicated. They could be drawn to the conservative economic policies of the Libertarian Party, but its position that government mustn’t forbid abortions or prevent gay couples being married or transgender people from using the correct public toilets in government buildings would leave many Republicans—especially the fervent fans of any of the “Christian” candidates—pretty hostile to the party (especially the fact it doesn't want to outlaw all abortions as the Republican Party does). So, the only Republicans who might vote Libertarian are those who are most “moderate”, so called, and not the base of the party or even necessarily a large number of voters.
Of the two camps, it’s much more likely that disaffected Sanders supporters would vote Green than that most anti-Drumpf Republicans would vote Libertarian. It’s more likely that such Republicans will hold their noses and vote Republican (most likely, in my opinion), anyway, or simply stay home. At the moment, it looks like what Sanders’ most fervent fans would do is a toss-up between voting Green or staying home. Sanders’ more pragmatic supporters would be the most likely to hold their noses and vote for Clinton as a realistic and utilitarian way of stopping Drumpf and the Republicans—or they’ll stay home rather than actively helping Drumpf win.
But, let’s play a wild fantasy game here, and let’s say that either or both third parties DO somehow pull off a miracle and win a state or two. Let’s also pretend that they were really big states, or maybe even that they won several smaller one so that together the third parties kept either major party candidate from getting the 270 Electoral Needed. What then?
The US Constitution’s 12th Amendment happens: If no candidate receives 270 Electoral Votes for president, then the House of Representatives chooses the president among the top three highest polling candidates. Each state delegation casts only one vote, and the winning candidate must receive a majority—26 of the 50 states (the District of Columbia doesn’t get a vote). This can continue for many ballots.
This happened under the 12th Amendment only once, in 1825, though in 1801 it happened under the old rules of Article II, Section 1, Clause 3, and that took 36 ballots. In both cases, politics played a role in who the House selected, and it certainly would now.
Similarly, if no vice president candidate receives a majority—and, since the president and vice president run as a team, if one doesn’t have a majority, neither will the other one—then the Senate chooses the vice president. Unlike the House, each Senator has a vote (again, DC gets no vote).
This matters because if the House is deadlocked and hasn’t chosen a president by Inauguration Day, then the Vice President chosen by the Senate is sworn in as Acting President. If neither chamber chooses someone by Inauguration Day, then the Speaker of the House becomes Acting President until one chamber or the other finally selects someone. This has never happened.
Here’s how this all works, using the current Congress as an example: Republicans control the House 246 to 188, and so, a majority of the state delegations. That matters because we have to assume that the state delegations would vote along party lines to select their state’s choice, since both sides would want a president of their own party (and, besides: When are they ever NOT partisan?! Moreover, the two times the House selected the president, it was highly political). So, if the current US House considered the results, Drumpf would win 34 to 13 (three states have evenly split delegations, but they wouldn't change the outcome if they decided on one party or the other). Similarly, Republicans control the current Senate 54 to 44, so the Republican vice presidential nominee, whoever he is, would be chosen.
However, because of the Twentieth Amendment, the new Congress would decide who was president, and there’s absolutely no way this far out to guess what the shape of the new Congress would be; the example here is for illustrative purposes only. However, if Democrats do well enough to completely change the partisan makeup of the House (especially) and Senate, then it’s unlikely that they’d fail to win the Electoral College vote.
So, due to the structure set up under the US Constitution, the difficulty for third parties to get on state ballots, the lack of attention they get from the news media, and the fact that they need to beat all the other parties in enough states to win 270 Electoral Votes, no third party candidate can be elected president. The ABSOLUTE best they could hope for is to come in third and win enough Electoral Votes to put the choice to the US House. But, since Congress is controlled by the two main parties, it’s pretty clear that no matter what happens, the next president will be either the Republican nominee or the Democratic nominee.
This system—which, though modified, is more than 200 years old—has become a barrier to electoral change, and skews the results to ensure the two main parties are entrenched. REAL reform is needed, but that’s a big subject in itself. The important thing about that for this post is that without real reform, the current reality cannot change, and the next president will be the Republican or the Democrat. There is no chance a third party will win the presidency.