[I later followed this up with "Democrats, socialism, PR, and Bernie Sanders."]

Among the small, but beneficial, ripples from the allegedly “inconclusive” result of the German election on September 18 has been some discussion of how multiparty democracy with proportional representation (as seen in Germany and most other democracies) compares to the strict two-party system (seen almost uniquely in the USA).

For example, Chris Lawrence suggests:

If the incentives for a two party system melted away, more likely than not our existing Republican and Democratic parties would melt away with them (or at least be transformed beyond recognition). And if you think our parties are bad now, wait until you see the parties led by Maxine Waters and Pat Robertson (or their acolytes) and comprised solely of their true believers.

I disagree that Dems and Reps would melt away or be transformed beyond recognition; more on that later. First, I want to stick to this “true believers” analogy, because Stephen Karlson also uses it:

Successful political parties in parliamentary republics are able to appeal to their true believers — who do not have to live in contiguous districts such as Berkeley, or Emporia — to obtain seats in proportion to the true believers’ share in the vote.

Now, let us assume that Stephen meant parliamentary systems with proportional representation (as implied by his own subject line) and not parliamentary systems more generally, given that some parliamentary systems (notably Britain and Canada, which are not “republics,” by the way) use the plurality (first-past-the-post) electoral system just as the USA does. Let us further focus only on the dynamics of legislative party positioning, and not government formation, since for the latter process the make-up of the legislature is almost irrelevant in a presidential form of government like the USA has.

Do parties in proportional representation (PR) systems appeal solely to their true believers? And would hypothetical coalitions between Democrats or Republicans and smaller parties render our two big parties more polarized than they are today (as implied at Betsy’s page)? No, and no. In fact, no one who has ever watched an election campaign in a European PR democracy or New Zealand since it adopted PR could possibly make such claims. Caricaturing the process in this way represents a fundamental—but, in America, widely held—misunderstanding of how multi-party democracy works.

In a nutshell, the point is that, with very few exceptions, parties in PR systems cannot afford to appeal solely to true believers if they seek any actual policy-making influence. Why? Because inter-election volatility (the movement of voters from one party to another) is much higher in multiparty PR systems. It is higher precisely because each voter has more choices—that is, more than one party that may be appealing to some aspect of his or her policy preferences. If parties are competing in an environment with this heightened level of competition, the ones that stick to their true believers quickly become rumps and find themselves marginalized.

In the quote above, Chris asks rhetorically, “if you think our parties are bad now…” Yes, I do think our parties are bad now, and it is largely because one of them is pulled too much one way by the likes of Maxine Waters and the other is pulled too much the other way by the likes of Pat Robertson (to use Chris’s examples). As Chris notes, our electoral system and two-party system generate broad parties that are internal coalitions of interests. And he is also right that all parties—even the small ones in some PR systems—contain internal electoral coalitions of interests. Get the Waters and Robertson acolytes out of the internal coalition of the Democratic and Republican parties and I, for one, will like both parties a whole lot better than I do now. And I suspect most voters would, too.

In broad “catch all” parties with loose internal organization like ours, political forces represented by the likes of Waters or Robertson are constantly digging in and attempting to keep their respective party from drifting too far to the center in the quest for the mythical “median voter.” A member of congress like Waters (or Frank or Conyers, etc.) can dig in her or his heels and, because our single-seat-district electoral system gives such members safe seats, these members never have to worry about losing influence by doing so. It is close to frictionless for them to stake out extremist positions in advance of bargaining over specific pieces of legislation. There are simply no electoral costs for them from doing so, and lots of potential benefits if they can keep the policy debate within their party skewed even a little bit in their direction, while at the same time appealing to their own relatively cohesive and ideologically extreme electoral districts. (The same analogy holds within either party, though we would need to use a congress member who was close to Robertson’s views, rather than Robertson himself, because he is not a member of congress, as is Waters.)

In a PR system, let us suppose Waters (and her allies, as well as her counterparts on the opposite side of the spectrum) split off and form their own parties. For the sake of argument, I am going to assume that the US has adopted MMP, like in Germany and New Zealand, though this thought experiment would not be radically different under most other forms of PR.

Now, in our hypothetical MMP system, Waters’s clout in congress (i.e. the share of seats her new party obtains) depends on her success at garnering votes from outside her own safe electoral district. She is now subject to competition with the Democratic party—which surely would survive, as would the Republican, albeit in smaller and more moderate form. The party led by Waters, Conyers, et al., is now tugged towards the center, because that is where it can gain the most in additional votes. That is where the inter-election volatility will take place, not at the fringes.

In conclusion, I do not deny that there are some parties and some party systems where PR and multipartism contribute to the kind of narrow ideological appeals that Chris and Stephen have in mind. For example, Israel, with its extremely low threshold and several tiny religiously oriented parties, or Italy from the 1950s to 1980s (but not today) with its very large and ideologically marginalized Communist Party. But these are not typical of PR systems more generally, and are not even remotely relevant comparative referents for a hypothetical PR system in the USA—for all its diversity, this country lacks the kind of rigid social divisions that give rise to parties like Shas or the former Italian Communists. Combine that with the probable high threshold our PR system would have (on the order of Germany and New Zealand) and our presidential form of government, in which the parties that can realistically elect presidents are sure to remain the most important players in the system, and it is clear that PR in the USA would hardly be as radical as Chris and Stephen fear. PR would moderate, not further polarize, our partisan competition.