Joyner and Taylor have addressed the question of whether two-party politics is here to stay in the USA or not. This is as good a topic as any with which to mark the first anniversary of Fruits and Votes!
Joyner (expanded at TCS Daily):
The Constitution all but assures that our politics will be dominated by exactly two parties.
I would say that the US constitution comes close to guaranteeing that parties will be programmatically weak, but not what their number will be. Joyner goes on to note the extent to which the “catch all” nature of US parties–closely related to their relatively non-programmatic nature–makes them so adaptable that the current two parties are likely to remain our two parties for a long time to come. He may well be right about that. However, it is worth focusing on the extent to which institutions–both the constitutional structure and the legislative electoral system–can be considered to “all but assure” the domination of “exactly” two parties. Is the relationship really so deterministic? Could multiparty politics emerge? Could multiparty politics even be emerging?
Let’s start with the constitutional structure of the executive. Only a few presidential systems have genuinely programmatic parties of the sort that typify all the advanced parliamentary democracies (and, to a significant degree, even most of the new parliamentary democracies of the post-Communist world).
The key distintion is that parties form in parliamentary systems to constitute the executive, based on their control of or bargaining power within the legislature. Parties form in presidential systems to elect an independent executive, or to transact with the executive from within the legislature. This is really a fundamental distinction, and someone should write a book about it. (Note to self: write this book!)
However, it is also the case that very few presidential systems have only two major parties. In part that is because very few presidential systems use our plurality system to elect the legislature. Nearly all presidential systems use proportional representation or some form of mixed system. But even in the Philippines, which uses a mostly plurality system, multiparty politics prevails: many parties, almost of all of which are programmatically weak.
It is important to realize that programmatic parties–by which I mean parties that present reasonably coherent policy platforms and act more or less as a unit in the legislature–typify parliamentary systems regardless of whether parliament is elected by plurality or proportional representation.
It is also important to realize that multiparty politics also typifies parliamentary systems, regardless of the electoral system. The UK is not a two-party system, and really has not been for about thirty years. Yet it uses a plurality (FPTP) system, just as the USA uses to elect its congress. And then there are Canada and India, which no one would confuse with two-party systems, notwithstanding their use of the plurality electoral system.
So, to sum up so far, we have presidential systems with multiparty politics and we have legislatures elected by plurality that have multiple parties. And then we have the USA–presidential and plurality–with two-party politics and with third parties barely present.
I agree with Joyner that part of the reason is the electoral college and, specifically, the “unit rule” by which states give all their electors to the candidate with the most votes (even if this is under 50%). But such a rule could generate separate regional party systems, and of course that is exactly what it did in the years leading up the Civil War. The 1948 and 1968 elections showed tendencies in that direction, too, though they were not sustained into subsequent elections.
The legislative electoral system used in the USA is likewise compatible with regional subsystems–just as has been the case in India and (to a lesser extent) Canada.*
So, while Joyner has correctly identified presidentialism, the electoral college, and plurality voting as factors that inhibit third-party success in the USA, the entrenchment of the two parties is actually somewhat difficult to account for, because either presidentialism or plurality voting is typically associated with much more competitive politics than we find in the USA. And, while the electoral college with its unit rule hampers national third parties, it might be expected to facilitate regional parties (and has done so in the past).
On the “here to stay” question, Taylor chimes in:
The only way there is going to [be] a substantial deviation from a two-party system in the US would be radical reform of the electoral rules that would shift us in the direction of proportional representation.
As much as I would consider it a gift from on High for PR to suddenly appear in the USA, this formulation actually puts it backwards. Where does PR come from? I can’t think of any case in which a change from plurality to proportional representation has occurred without a prior emergence of competitione among three (or more) parties.
Electoral systems shape party systems (where have I read that?), but major electoral reform follows party-system change, not vice versa.
And, of course, the arguments allegedly favoring plurality elections are all post-hoc. The plurality system was never consciously designed. (Really, presidentialism, with the concept of national electoral campaigns for separate executive office, never was, either.) Plurality systems were simply an inheritance of pre-democratic forms (and presidentialism an adaptation of a very different idea of executive structure born of expedient compromise at the US Constitutional Convention).
The arguments in favor of PR, on the other hand, began to emerge before actual electoral reform had made much headway. The set of national or state/provincial jurisdictions around the world that have adopted or made affirmative decisions to keep plurality is close to an empty set. When the issue is seriously debated, PR almost always results, in some form. But, again, such debate happens only after three or more significant parties are present. (And, of course, there are exceptions where majoritarian-leaning mixed systems replace PR or other systems more favorable to third parties, but it is almost an iron rule that no one consciously adopts plurality, as opposed to reinstates it after an authoritarian period or inherits it from a colonial or authoritarian regime.)
So, what would it take to break the hold of two-party politics? It would take the emergence of one or more programmatic parties that threatened the electoral position of one or both of the major parties.** Such a party could not just exist at the presidential level, a la Ross Perot. It would have to contest seriously at least some House and Senate races.
The emergence of multiparty politics could come in the form of a party that plays “spoiler” and thereby makes one of the major parties’ internal calculus about the electoral system shift.*** That would at least put electoral reform on the agenda, and even if the other major party were to be quite happy to see its major competitor “spoiled,” once PR is on the agenda, experience in other cases where reform has been adopted or seriously debated says the genie (and genius!) of the idea of PR can’t always be put so easily back in the bottle(neck) of big-party politics-as-usual.
* Canada now has something close to three-party politics nationwide, with only Quebec having a distinct regional party in federal elections. India, on the other hand, has numerous parties that contest only in one or a few states, as well as national parties that refrain from contesting districts in some states out of deals struck with local parties.
** The first part of this–the emergence of new parties–has been underway for some time, as I have shown with graphs. In most US presidential, House, and Senate elections since 1990, neither major party has won 50% of the vote. This has yet to rise to the level of threatening the major parties, however–at least in a way that has changed the debate. (In the 1968, 1992 and 2000 presidential elections, third parties were clearly a factor; we probably need many more such elections!)
*** The extent to which the major US parties are non-programmatic complicates this, however, to the extent that parties are much less cohesive, strategic actors in the way that they tend to be in parliamentary systems. However, the parties–especially the Republican–have clearly moved in a direction of acting more like programmatic and strategic decision-making units in recent years.