« Housekeeping: Extended Posts? | Main | The Bush Landslide of 2000? »

October 08, 2004

More on the Incumbent Rule

Several readers took strong exception to my discussion of the incumbent rule, the idea that undecided voters tend to "break" toward the incumbentchallenger just before Election Day. Gerry (of Daly Thoughts) was most succinct:

We are a month away from the election. Those who are undecided now are not more likely to break for the challenger. At least, that is what the history of Presidential elections says (lower ticket races may be different). Perhaps those undecided the day or two before the election are, but we are not there yet.

To which I say, true, but that was not my point. The "incumbent rule" is about the "break" toward the challenger between the last poll and Election Day. From a month or more out, Gerry is right, presidential races do not seem to break with much consistency either way. Looking at Gallup's collection of presidential election polling charts dating back to 1936, I see trends favoring four challengers (Wilkie 1940, Goldwater 1964, McGovern 1972, and Dole 1996) and four incumbents (Roosevelt 1936, Truman 1948, Eisenhower 1956 and Ford 1976). In 1980, Jimmy Carter gained support during September and October, but then Reagan surged in the final week after the debate. In 1992, George H.W. Bush lost a few points in September then gained them back in late October. (See some possibly different interpretations here, here and here).

The point of all this is not predicting trends to Kerry or Bush over the next three weeks - if you can do that, your crystal ball is better than mine - but how to characterize where the race would stand "if the election were held today." Should news coverage focus so relentlessly on where the race stands at any given moment? Probably not, but there is no question that it does. Thus, if we want to accurately characterize where the race stands right now, the incumbent rule tells us to focus more on the incumbent's percentage relative to 50% than the margin between the incumbent and the challenger.

It is also a misconception that the race over the next three weeks is only about appeals to the completely "undecided" (and efforts to mobilize base constituencies). Voters may still shift from one candidate to another or to undecided. The just released ABC/Washington Post poll, for example, shows only 3% of likely voters completely undecided, but another 11% who could "change their minds" about the candidate they now support. Similarly, the new Marist Poll shows 6% undecided, and another 4% who support a candidate but say they "might vote differently" on election day.

MyDD's Chris Bowers also pointed out that I understated one aspect of his data: "86 percent of the total number of undecideds broke for the challenger" in the 28 presidential polls he examined (not 86% of the polls - emphasis added). He also noted that the size of the break is typically modest, only 2-3 points, since the pool of true undecideds is small in the final week. However, if the current standings persist, that 2-3 points could be crucial.

Finally, one important caveat: A number of races defied the incumbent rule in the 2002 off-year elections. Commenter "Dr. X" was right that "many low polling sub-50% incumbents, such as Wayne Allard, Tim Johnson, Mary Landrieux Gray Davis...were re-elected." Is the incumbent rule moot post 9/11? I doubt it, but we should remember that the rule, while based on solid evidence, is still more art than science.

[Continue with an application of the incumbent rule in Ohio]

Related Entries - Incumbent Rule, Interpreting Polls, The 2004 Race

Posted by Mark Blumenthal on October 8, 2004 at 07:56 AM in Incumbent Rule, Interpreting Polls, The 2004 Race | Permalink


"the incumbent rule, the idea that undecided voters tend to "break" toward the *incumbent* just before Election Day."

Is this a typo?

Posted by: Chef Ragout | Oct 8, 2004 8:45:16 AM

--"the incumbent rule, the idea that undecided voters tend to "break" toward the *incumbent* just before Election Day."
Is this a typo?--

Argg..yes. Good catch, thanks

Posted by: Mark Blumenthal | Oct 8, 2004 9:03:40 AM

Data showing 86% of the undecideds breaking towards the incum...I mean, challenger is a powerful statistic. It is the type of stat that can demoralize any incumbent.

However, post-November 2nd, we could see a black swan in the guise of a 100% break for Bush, and it would not likely move the 86% much (unless the percetage of undecideds was remarkably large, and in a 50/50 nation, I doubt that to be the case.)

This stat is powerful in the aggregate, but, in any one election, it is meaningless.

Without the financial wherewithal to take out a full-page ad in WaPo or NYT, this point has little chance of advancing into the realm of conventional wisdom in three plus weeks time before this election.

(And as statistics are generally unexamined, I doubt even the full-page ads would help.)

Posted by: Eric | Oct 8, 2004 10:17:06 AM

The Johnson and Davis races weren't typical.

Johnson was polling at less than 50% leading up to election night? Good for the polls, he won with less than 50% of the vote - with a winning margin of only 500 votes.

Davis would not have been reelected if we had a viable alternative ... as you may recall, we kicked him out of office as soon as we had the chance. Davis did his best to lose that race. He dragged down the rest of the Democratic ticket and voter turnout with it. You kind of know you have a problem when you only pull 80% of the vote running unopposed in the primary.

I worked on the Johnson campaign and live in California, so I don't really have insight into the other two races.

Posted by: Devin | Oct 8, 2004 12:16:55 PM

Undecideds can also break towards the couch and decide not to vote. This is why I have such a problem with Zogby pushing his respondents so hard...I suspect he is counting a bunch of people who won't actually show up at the polls on election day.

Posted by: Blue | Oct 11, 2004 11:16:30 AM

I have two reasons to doubt the relavence of the "incumbent rule" to this election, associated with the observation that this campaign has not been the norm for campaigns involving incumbents. Everything I've heard from people on TV says that the Bush campaign has done a tremendous job of making this campaign a referendum on the incumbent as well as on the challenger. If this is the case, does that not make this election more like one for an open seat? My second reason for doubting the relavence of this rule is the following question: does the rule apply in a time of war? I tend to think that undcided voters might do the "safe" thing in a time of war and break the opposite direction - for the incumbent. That's a question I don't have the experience to answer, and it raises the second question of whether or not the people of this country (and specifically undecided voters) think we are at war. Realize I'm not doubting the authenticity of this rule, I'm just stating a couple of things that could make this election one of the exceptions to said rule.

Posted by: PABlue | Oct 26, 2004 10:46:22 PM

The comments to this entry are closed.