Steven Taylor argues that one of the main reasons that we don’t have a third party is that we have the primary process as opposed to the parties selecting its nominees:

Indeed, I would argue that one of the main reasons we do not have serious third parties in the US is that the primary process allows a method by which groups dissatisfied with a mainline party to work from within that party (e.g., the reason that Ron Paul always ran for congress as a Republican, rather than as a Libertarian). Of course, the main manifestation of this phenomenon at the moment is the Tea Party. The Tea Party faction of the Republican Party has no incentive to go the third party route, but every incentive to take the primary route. Players play by the rules of a given game, and they adapt to the options that a given game allows.

It’s certainly the case that political parties in the United States are nimble. I can also believe that they are nimble in a way that prevents third parties from rising up because their issues end up getting absorbed into the main parties.

I’d argue, though, that in the constellation of reasons that we don’t have continuous third parties, it’s a relatively minor one. The bigger issues are well-explored. I will be exploring them further in a future post, but our lack of proportional representation, and our lack of a parliamentary system are the two largest factors. While there are other cases of nations that lack proportional representation that nonetheless have multiple parties, the electoral college throws yet another wrinkle on it because our mechanism for handling non-majority presidents provides significant disincentives.

In the UK, if none of the three parties get a majority, there is a process of handing the government to a coalition of sorts. It’s not perfect, but it’s there. The center-right party gets a plurality over the two center-left parties and what happens? The center-right party gets the executive. Or maybe that doesn’t happen and the two center-left parties form a coalition. What happens in the US when a candidate fails to garner a majority? Well, who knows? You have to get a plurality of a majority of the electoral votes. And if nobody does? Well, we do have a system for that, but it’s an incredibly lousy one without a semblance of predictability. This is above and beyond a first-past-the-post system and its limitations.

In the comments, Taylor mentions comparable countries that have room for alternative parties despite having elements similar to our own. In addition to the parliamentary countries, he mentions India which also has an electoral college. As a matter of custom, though, theirs works differently from our own. Most notably, perhaps, their selection system can cope with the question of what happens when nobody gets a majority. (Their president is actually typically elected unanimously, but I assume this only occurs because the outcome is not in doubt.)

Because of all of this, alternative parties in the US have to contend with the fact that they have no chance at the executive and can, at most, affect legislation. I have difficulty imagining that being successful even with party unity. Typically, when we do have independent legislators at the national level, it is with the implicit understanding that they will be aligned with one of the two major parties and the voters will know which one (Sanders, King, Lieberman, Goode in 2000, Jeffords if he had run again).

My concern with moving to a system where candidates are subject to their party’s preferences (and then voters choose between parties) is that we wouldn’t see the flexibility between parties that Taylor refers to and instead we would be quashing intraparty reforms where they might be necessary and democratic. I certainly have my issues with the Tea Party, and a part of me wishes that the “adults can take charge!” of the GOP, but the adults in the party were content to deny not just Christine O’Donnell and Richard Mourdock their day, but also Rand Paul and Marco Rubio. And perhaps unlike Taylor, I don’t see their day having come in an emergent alternative party. I may not like the trajectory of the GOP under the Tea Party, but I’d prefer it be sorted out democratically rather than by committee. It was a committee that chose Ken Cuccinelli.