David R. Henderson  

The Power of the Median Voter Theorem

PRINT
Doing the Best I Can: S... The Pathos of Doing the Bes...

Political commentator Michael Barone writes:

So despite California Democrats' hopes that an early presidential primary date will give the state greater influence in selecting a Democratic nominee, past history suggests that that's not likely -- and that there's a risk that California, newly installed at the left extreme of the political spectrum, will tilt the process toward an unelectable left-wing nominee.

See Michael Barone, "California Democrats' early presidential primary: Unintended consequences?" Washington Examiner, October 2.

University of Tennessee law professor Glenn Reynolds quotes more extensively from the well-reasoned article and then comments, "I see no downside to this."

I would have thought that the downside, from Glenn's conservative viewpoint, would be obvious.

It's something called the median voter theorem. The median voter theorem states that "a majority rule voting system will select the outcome most preferred by the median voter". Definition taken from Wikipedia. The theorem applies best in a political system in which two parties dominate and in which voters can be arrayed along a spectrum. Glenn obviously believes that that applies to the current U.S. system. His thinking is that if the Democrats go further left, they will lose, which means the Republicans win.

He's right.

But that's where the downside comes in. If the Democrats go far to the left of the median voter, what's the Republicans' best response if their goal is to win? It's to go further left themselves (not further left than the Dems but further left than they would have gone against a more-moderate Dem candidate) to pick up all the voters on their side of the median plus, say, a slice of 10% on the other side. If they go moderate left, they pick up these voters. So yes, the Republicans win. But Glenn's cherished policies lose.

This is exactly what happened in 1972 when George McGovern was well to the left of the median voter. Nixon ran a campaign that was fairly left. I remember having just arrived in the United States in September 1972 and hearing an ad about how Nixon had used naked presidential power to shut down a polluting factory without having any particular law to draw on. "That's a great anti-Nixon ad," I thought when I heard it. Then I heard the end: "Young people talk; President Nixon listens." The ad was bought by the Nixon campaign.


Comments and Sharing






COMMENTS (14 to date)
JFA writes:

It's been a while since I read the literature, but doesn't the median voter theorem break down in multidimensional settings. So we have to ask what dimensions the hypothetical Republican would move left on. I'm not really sure what direction (left or right) pro-trade would be in and the current anti-immigrant zeitgeist raging through the Republican party is pretty bad. If moving left meant that you got a Republican who was more pro-market (not just pro-business) and more pro-immigration, I don't see a problem.

David R Henderson writes:

@JFA,
You’re absolutely right. I’m pretty sure, from the context of Glenn Reynolds’s other posts, that he has in mind movements to the left that he would not like. One of these is probably immigration, which you and I like. But that’s why I emphasized that this doesn’t work from Glenn’s conservative viewpoint.

Hazel Meade writes:

It would probably be better to simply hold ALL primaries on the same day. That way early states don't tend to bias the nominee towards people that compete well in those states but not in others.
Can't the national party impose a requirement that all of the states hold their primary election at the same time?

Matthias Goergens writes:

A sensible reform would be to just hold the primaries using eg range voting..

Since primaries are just party internal, no laws would need to be changed, or would they?

(Range voting would also make sense for other single winner elections in general. But that would require changing laws.)

Michael Byrnes writes:

Does this explain recent political trends?

I think there's a strong case to be made that the Republican Party has drifted rightward since the days of Reagan. And that Bill Clinton was elected by moving rightward. So this one seems to fit.

I'm not sure any election since then fits this pattern.

Right Wing House Music writes:

A republican would be far more satisfied with a slightly left-leaning victory for the Republicans than a moderately left-leaning victory for the Democrats.

Hana writes:

Given California's open primary voting, isn't an earlier primary more likely to give support or momentum to a more liberal Republican candidate regardless of a median voter theorem?

Shane L writes:

This is fascinating and I'm not familiar with the theory. Supposing polls give one party a very slim chance of victory in the face of a popular opponent. Should they simply field the most extreme candidate possible to swing the other party towards the centre?

David R Henderson writes:

@Shane L,
This is fascinating and I'm not familiar with the theory. Supposing polls give one party a very slim chance of victory in the face of a popular opponent. Should they simply field the most extreme candidate possible to swing the other party towards the centre?
When you say “should,” you’re asking from what viewpoint? If the party’s main goal is to affect policy, then yes. If, however, the party’s main goal is to get elected--and that usually is the case--then no.
Having said that, I think the 1964 Goldwater debacle illustrates the median voter theorem beautifully, but raises another problem. First, it illustrates it because one of the main issues was dealing with the Communists, especially in Vietnam. Goldwater’s extremism led LBJ to be probably more hawkish than otherwise. That’s why we got the old joke, and I think it might not have been a joke but might have been real, about the guy saying, “I was told if I voted for Goldwater, we’d bomb North Vietnam. So I voted for Goldwater, and, sure enough, we bombed North Vietnam.”
But here’s the problem. There had been a coalition of Republicans and southern Democrats that had stood strongly against socialized health care from Truman on. With Goldwater bringing down a lot of Republicans in the House and Senate, this coalition lost power and LBJ got Medicare and Medicaid. Those two programs alone account for the lion’s share of the federal government’s spending increases in the last few decades.

Roger Sweeny writes:

This is how Republicans have gotten their majorities in the House and Senate. We won't take away anything government has been giving you (and we'll make promises we can't keep).

Thus "repeal Obamacare" fell victim to the fact that any replacement would visibly hurt some people. As it was, all the "repeal and replace" bills were actually "modify Obamacare."

robc writes:

Roger,

I don't think Senate Bill 222 qualifies as "modify Obamacare", but it never moved in committee.

Thaomas writes:

I don't think the primary system works to produce candidates most likely to appeal to the "median voter." Making voting easier in primaries might help a little.

Adam writes:

The Goldwater-Johnson example seems exactly right, but Nixon was no conservative. Indeed, he seems to be the GOP left-leaning choice subsequent to the Goldwater loss and Johnson's moving right.

Overall, the median voter model seems powerful given the sequence of party candidates and results in the 64, 68 and 72 elections. Parties are always so rational. What's the explanation of Mondale in 84 or Dole in 96?

David R Henderson writes:

@Adam,
The Goldwater-Johnson example seems exactly right, but Nixon was no conservative. Indeed, he seems to be the GOP left-leaning choice subsequent to the Goldwater loss and Johnson's moving right.
Exactly.
What's the explanation of Mondale in 84 or Dole in 96?
I don’t understand your question. What would you like me to explain: why they lost or why they postponed themselves where they did.

POST A COMMENT




Return to top