The US has what is called a two-party system, which is when, as the name implies, there are two parties that dominate political discourse, in the US the Democrats and Republicans. Not only that, the US is a particularly extreme form of a two-party system. The United Kingdom is considered to have a two-party system, where the Labour and Conservative Parties are the clear frontrunners and frequently either is able to make a majority by itself. But there are other parties represented in parliament and sometimes neither Labour or Conservative have over half of the seats and as a result must form a coalition with another party in order to achieve a majority. In the US, however, it is a rarity to have even one person from a third party be in the United States Congress. One may point to Independents, but not only are they rare, they generally are for all practical purposes a Republican or for all practical purposes a Democrat. For example, the two Independents in the US Senate right now are Bernie Sanders and Angus King, who are essentially Democrats (certainly, they caucus with Democrats). Yes, they may not be your "typical" Democrat but a good number of those who are officially listed as Democrats would not be considered your "typical" Democrat either.
What exactly causes the dominance of these two parties? There are various reasons, but one of the biggest is first-past-the-post voting being used almost everywhere in the US. If you are unaware, first-past-the-post voting essentially says that whoever gets the most votes in an election wins. In other words, if one candidate gets 42%, one gets 32%, and another gets 28%, it means that the person who got 42% will win despite not winning a majority. It also means that something has gone horribly wrong in the world of math because they all total to 102%. Such a system, while not guaranteeing a two party system, strongly favors it, primarily due to concerns of your vote being "wasted."
There are various suggestions on how to change this up, but in my view the simplest would be to implemented Ranked Choice Voting in all elections, where one ranks the candidates in preference. A key point here is that even if someone doesn't understand the mechanics underlying it, they can easily grasp the idea of ranking candidates in how much they like them.
Here's how it works. After everyone votes for the candidates by ranking them, all of the first choices are then added up. If a candidate wins a majority, they win the election. If not, whatever candidate got the least votes is thrown out, and anyone who voted for them instead has their second choice counted as their vote. If someone gains a majority, then they win; if not, the remaining candidate with the least votes is thrown out, and anyone who had them as their first choice will have their vote re-assigned to their second choice (or their third choice, if their first and second were the two eliminated candidates). This continues until one candidate has a majority and is declared the winner.
The way this breaks the two party system is fairly obvious: Under the current system of first past the post, one worries about throwing their vote away for a candidate. Under the above system, however, that no longer happens. Let's illustrate.
Suppose there is Candidate A, Candidate B, and Candidate C. A and B are the clear frontrunners, with C being very unlikely to win. You like Candidate C the most, are ambivalent on Candidate B, and hate Candidate A. So you face the dilemma: If you vote for Candidate C, there is a high probability your vote won't do anything at all, and you risk handing Candidate A the win. So do you vote for Candidate B, who you don't particularly like but will help prevent Candidate A from winning? Under Ranked Choice Voting, you don't have to worry, because if Candidate C is unable to win, your vote will be "transferred" to B.
Now, this would likely not end the two-party system in the United States. Australia has ranked choice voting and, like the US, has two major parties that are significantly ahead of the others in terms of electoral success, the Labour Party and Liberal Party (due to political shifts, the "Liberal Party" is ironically the conservative one). But they don't control discourse to the extreme extent that the Democrats and Republicans do.
Ranked Choice Voting is not the only other possibility. Perhaps some kind of proportional representation could be used. But I favor Ranked Choice Voting for several reasons. First, it's the easiest to implement. Proportional representation requires a major shift to how officials are elected--Ranked Choice Voting is relatively small. Second, it is simple and easy to grasp.
If you are wondering about the President, note that one does not even need to get rid of the electoral college under RCV, as you simply have the RCV apply on a state-by-state basis. Granted, I know many would like to see the electoral college go away, but to do so would require a constitutional amendment (very hard to accomplish!). The point is that you can do Ranked Choice Voting within the current constitutional framework of the electoral college, as it allows states to decide how to allocate the electors--they can easily do this via ranked choice voting, should they choose.
Unfortunately, implementing this could be difficult. If there's one thing Republicans and Democrats agree on, it's that they like staying in power. Maine managed to implement Ranked Choice Voting, but to get it done they had to essentially bypass their legislature via referendum; not all states have that ability. Still, one state implemented it, so perhaps others will follow.
There are some reasons to be hopeful. For about a century, Senators were not elected by the people of the state, but by state legislatures, but a constitutional amendment was passed to change that. Passing a constitutional amendment requires 2/3 of the Senate (and House) and 3/4 of State legislatures to agree to pass it. In other words, despite the fact this could result in all of the Senators losing their positions due to the change, and despite the fact state legislatures were giving up power through this change, people were able to convince them to pass the amendment. Further, this isn't a full loss for Democrats or Republicans. Ranked Choice Voting all but eliminates the possibility of a third party candidate being a "spoiler", which would be to their advantage. Thus, there is at least hope for this to happen in the US.
But in the meantime, what to do? Well, even beyond first past the post, I feel there are some ways to help break the duopoly. A major problem with many third parties is that they tend to just be more extreme versions of Democrats or Republicans. When you are pulling from only one party, it's difficult to win. So to become truly viable, a third party has to be offering something that's a mixture of both of their positions.
There are two major categories that political positions fall into. There is social, and there is economic. Republicans have conservative social and conservative economic positions, whereas Democrats have liberal social and liberal economic positions. But what about those voters who have conservative social and liberal economic positions? Or liberal social and conservative economic positions? They are not being represented by those two parties. What third parties are there?
Socially liberal, economically conservative is represented by the Libertarian Party. Socially conservative, economically liberal is represented by the American Solidarity Party. (note that these descriptions are oversimplified, but give you the general gist of their parties) While the Libertarian Party is the much larger of the two--indeed, it is the largest third party in the country--I feel the American Solidarity Party has the potential to be much bigger and provide a real alternative to the duopoly we have.
Why do I think that? Well, a picture tells us a lot:
As we can clearly see, a very substantial portion of the electorate falls into the socially conservative, economically liberal quadrant (upper left). That is the portion of the population that the American Solidarity Party has appeal for. Meanwhile, the socially liberal economically conservative quadrant (lower right) that the Libertarian Party represents has the smallest amount of the population.
Why is the Libertarian Party currently more successful than the American Solidarity Party, then? I feel it's because the LP has been around for decades whereas the ASP is relatively recent (founded in 2011). It takes time and effort to build up a political party, especially when the odds are stacked against you. But the amount of strides they've managed to make in that time are actually impressive. The mere fact that any member of the party has been elected somewhere already puts them ahead of about 99% of the third parties in the country.
So if you want to break the duopoly, the best way in my view would be to implement Ranked Choice Voting. In the meantime, I believe that the Libertarian Party or American Solidarity Party are our best shots at a third party rising up to become a real contender. The Libertarian Party has the advantage of being much more entrenched and with a greater level of electoral success, but I believe the chart shows the American Solidarity Party has more potential to rise up.
But all of this is a bunch of musings. What can people actually do about this?
I am not sure of the right path to take for Ranked Choice Voting, unfortunately. But when it comes to third parties, the options are fairly simple on how to support them. The obvious thing is to vote for them, but an issue with that is that (1) they may not have a candidate on your ballot, and (2) it's the time before the election that ends up making the most difference.
What's more beneficial is to actually join up with one and work to promote it. But not everyone has the time or zeal to do so. Bumper stickers and yard signs can also help, but those can feel awfully tacky and one may be hesitant to broadcast their politics in such a way. So if you are uninterested or unwilling to do those, I submit the following: Make a small donation to them. A party needs money to be able to get itself known--and to get ballot access!--but in order to have that money, people need to donate.
Indeed, consider how many people complain about the duopoly. If every single one of those people made even a $1 donation to a third party, that third party would instantly become a real force in politics. Certainly not to the extent of the Republicans or Democrats, but I expect they could elect at least a few people to the House of Representatives, and in doing so would raise their profile and could reach further success in the future.
So if you have actually read all of this, here is my request: Go to the website of a third party and donate at least one dollar. This should take no more than a few minutes and, of course, the monetary charge is minimal. I think the American Solidarity Party has the best odds of making real change (donation page available here), but if you have major problems with them you can try a different third party. Now, you might think that's not much, but every bit helps, and again: If everyone who complained about the duopoly would do even just this, we'd start seeing real change. So that is my request to you: Go over and donate one dollar or more to a third party. It'll take less time to do so than it did to read this post!