It happened again last night: I found another politically ignorant person preaching about how much better things would be if only we had a real third party in the United States. (To be clear: I’m not saying all people who feel this way are politically ignorant, just that this guy was.) Let’s see if I can simply explain why this is a non-starter. I do not disagree with the sentiment; rather, I consider myself personally agnostic on the subject. My objections to this line of thinking are based in how impractical it is to change the laws and constitution to bring about such a system. This piece explains what causes the 2-party system we have, what changes would need to take place in order to end it, and an analysis of how likely advocates are to successfully enact those changes.
There is one main aspect of our democracy that lets the two-party system continue: first past the post voting.
As the above video points out, gerrymandering and reliance on districting (such as state-level winner take all in presidential elections) also contribute to this, but reforming those would not be enough to allow viable third parties to exist. The game theory of first past the post is sufficient to ensure convergence to two parties.
So let’s assume the United States can transition to a multi-party system. To do that, it clearly must end first past the post voting. We have two general approaches in our current political system for how to change our elections and get this done…
The Federal Level
The federal government is supreme, but the constitution clearly delegates power to hold elections to the states. This means we need a constitutional amendment that dictates how states run their elections in order for the federal government to initiate the change.
Proposed constitutional amendments must pass both chambers of Congress with a 2/3 majority vote, and are then sent to the states for 3/4 of them to ratify. This is intentionally really hard, and requires lots of representatives in both federal and state legislatures to agree to end first past the post voting. Therein lies the problem: the legislators who must vote to pass and ratify such an amendment are predominantly members of the two major political parties and therefore would be acting against their own interests. Members of Congress, in particular, have spent years cultivating relationships with colleagues, interest groups, donors, and party organizations; they are not going to throw all that hard work away so easily.
So maybe we need to boot out all these corrupt politicians and replace them with independent, nonpartisan legislators to enact the people’s will? One can try, but it will not happen because we have first past the post voting that protects major-party candidates. We have reached a paradox. Also take note of Barack Obama and Donald Trump, two populist candidates who quickly abandoned promises that threatened the normal operation of government almost immediately after taking office. We cannot trust any candidate who pledges to blow up a system we do not like but they would control or benefit from if elected.
There is one more possibility to get an amendment: two thirds of states can call for a Constitutional Convention under Article V to bypass Congress. This would still require taking independent control of states, and is addressed below. In any case, it is not likely to actually happen as Congress would probably draft its own amendment (possibly watered down or poison-pilled) to quash support for such a convention.
The State Level
This option offers the most hope, although prospects are still grim.
I count 11 states which do not use pure first past the post voting in their elections today , with a combined Congressional delegation of 163 members (30 percent of all members of Congress). I chose not to count four states which have partially enacted voting reforms, and there are several states in New England like Maine that are fiercely independent and could be low-hanging fruit.
The state approach would require getting states to pass reforms one at a time. The same paradox as before, though, exists with partisan state legislatures that would have to enact the laws to make it happen. Furthermore, some past reforms that went too far have run afoul of federal law and constitutional conflicts , so Congress may need to assist anyway.
The most hope should be in states with lax rules for ballot initiatives. However, most of the states with such rules already are on the list of states which have done away with first past the post. One exception is Oregon, whose voters keep rejecting attempts to switch to top-two primaries.  Any advocate of such reforms should build a deep understanding of why they keep failing here.
I estimate that these state-level reforms would not be a serious threat to the main political parties until at least 3/5 (60 percent) of Congress represents states with voting systems that allow more than two parties to thrive, so the country has a long way to go. My reasoning: if a centrist third party formed and won 1/3 of those states’ members of Congress, it would have 1/3 * 3/5 = 1/5 (20 percent) of the total seats, while the Democrats and Republicans would each hold 35-45 percent. At this point, the third party could form a functional ruling coalition with either of the other two parties, including enough margin to allow for some defections. There numbers are also where I would expect an equilibrium to be; it may take 10 years or more after reforms are in effect to see anything like this.
So considering how much needs to be done, how difficult it would be, and how long it would take, it seems pretty unlikely to work. I feel that people who are upset with the way our government works would have more success focusing on other efforts to make our system work better.
The Third Option: Revolution/Overthrow the Government
I’ll just quote John Lennon on this one:
You say you want a revolution
Well, you know
We all want to change the world
You tell me that it’s evolution
Well, you know
We all want to change the world
But when you talk about destruction
Don’t you know that you can count me out
- Eight states rely heavily on Primary Runoffs (National Conference of State Legislatures), a flawed but still better system that first past the post. I am not counting Vermont or South Dakota in this because their use of runoffs is pretty limited. Three more states use Top-two Primaries (Ballotpedia) which have a similar effect. Here, I am not counting Nebraska which only uses top-two for some races. These systems, while flawed, are better than first past the post and, if enacted nationwide, might be enough to dismantle a 2-party system.
- Alaska’s Primary Election History (Alaska Division of Elections)
- Oregon Open Primary Initiative, Measure 90 (2014) (Ballotpedia)
- The Two-Party System: Definition, Advantages & Disadvantages (Study.com)