The logic of third party politics

My friend Matthew Richards has an essay posted at Progressive Action NH criticizing nearly every conceivable voting strategy this November. I agree with him about a lot of things, but mostly I'm using our disagreements as a springboard for defending third party politics.

In regards to Jill Stein, Matthew summarizes the classic argument against third parties:

Why not vote for Jill? We’ve all heard it. Jill knows it herself. She’s not going to win.  She’s somehow “taking votes away” from Obama.

He continues:

But is that a reason for not voting for her?  I think it’s a terrible reason not to vote for her, because people not following their consciences is part of what has gotten the world into the huge mess it’s in right now.

I agree that it's a terrible reason, but I don't trust my conscience as much as Matt does, so I rely on a more strategic argument.

In a sense, votes for Jill Stein do take votes away from Obama, and they could throw the race to Mitt Romney. And practically everyone voting for Jill Stein would prefer Obama to Romney. Combine this with the impossibility of Jill Stein winning (the prediction market Intrade estimates less than a 0.1% chance, as of Oct. 7th), and voting for Obama appears to be the logical choice. Only a masochist or an ignoramus would vote for Stein.

But if we take a longer view, the strategy can flip.


Let's take a step backward. Candidates don't appear out of a vacuum. They are selected by their respective parties in the primaries. Once you know what's going on, primaries are surprisingly easy to understand. While nominally democratic, to a large extent they are controlled by die-hard party insiders. Party insiders can't directly rig the ballot box, but they exert a huge influence by contributing endorsements, money, advice, personal connections, and a variety of other resources to their favored candidates. Taken together, that packs a big punch, and it means we can often predict primary outcomes just by understanding party insiders.

To connect this discussion back to third parties, we need a clearly defined model of party insider decision-making. My personal favorite comes from Kathleen Bawn, Marty Cohen, David Karol, Seth Masket, Hans Noel, and John Zaller. In brief, they argue that, for the two main parties, party insiders look for the nominee who can further their interests the most while still winning the election. Voter ignorance gives them plenty of leeway here, though uncertainty and competition lead to losses in about half of the races.

In a hypothetical world where everyone votes for one of the two parties, party elites follow a clear strategy– they promote candidates that are just close enough to the political center to attract 51% of the vote. If they don't think a particular candidate will garner enough votes, they look for a more moderate candidate who can take more votes from the opposition. Since we've assumed that voters will stick with the two main party candidates, as long as (in the case of the left-leaning candidate) he or she doesn't move to the right of the right-leaning candidate, the candidate can gain more votes by moving rightward towards the right-leaning candidate. The right-leaning candidate follows the same logic, moving leftward towards the left-leaning candidate. In the conclusion to this scenario, both candidates take practically identical positions smack dab in the political middle, splitting the vote.

(This story– known as the median voter theorem in academic circles– was originally based on a theory of business location. Suppose there are two hot dog vendors on a beach. They charge the same price and compete on location alone, and each customer buys a hot dog from the closest vendor. If both of the owners are smart, they will end up right next to each other in the middle of the beach, with each vendor serving all the customers on one side. If one vendor were to choose an off-center location instead, this would give the other vendor an opportunity to sneak up right next to her and take a larger share of the customers. Thus, the middle is the likely outcome, for the same reason the political candidates chose the middle.)

Whenever people protest candidates by staying home, or by voting for third parties, they complicate the strategy. Moderate candidates may pick up votes from the opposing candidate, but they may also lose votes from disillusioned supporters of their own party. Party insiders must weigh both effects when choosing candidates. If moderation loses more votes through protests than it gains from the opposing party, the insiders will prefer the less moderate candidate.

Uncertainty completes our argument. Party insiders work with limited information about the electorate, so they must grapple with uncertainty about the distribution of political attitudes. A person voting, for, say, the Green Party, is basically waving a bright flag saying, "Hey, I just wanted to let you know that if your candidate were more like the Green candidate, you could get my vote." And that hard data influences the choices of party elites in the next round of primaries. The effect, in many ways, is similar to a letter written to a local representative. The letter probably won't change the representative's personal opinions, but it gives him useful data about local voters. If it surprises him, he might change his votes in response.

Matthew anticipates this argument, to some extent. He counters that "Protest votes do not “register dissent” the way we’d like them to". And thus they fail to effect the primary choices of the major parties. But I totally disagree. Just ask a committed Democrat about Ralph Nader and Al Gore in 2000. They got the message loud and clear. Some leftists disliked Gore and voted for Nader in protest, and these Green protest voters cost Gore the election (or so the story goes).

As a result, it can make sense for many libertarians to vote for Libertarian Party candidate Gary Johnson. (In state and local elections, they may agree more closely with the Republican nominees, and vote differently.) Many leftists could very well get more bang for their buck by voting for Jill Stein. To those who oppose elections altogether, in particular the "vote for nobody" group, this reasoning suggests they should consider going to the polls and actually writing in "nobody", so that their protest is indisputable.

I've been very disappointed with both the Democratic and Republican nominees on some foreign policy and civil liberties issues (for example, neither seem to care about terrorizing Pakistanis with incessant drone attacks or imprisoning Bradley Manning for years without a trial), so I would love to see third parties siphon large numbers of voters away from them. I doubt the D's and R's will respond to anything else.