Onward with my Primary Polling Primer. In the first
two
installments, we talked about turnout, or rather, how national polls tend to sample
a broader population than actually participates in the presidential primaries
and caucuses. Today, I want to turn to something even more important to the
"accuracy" of those national vote preference polls: Timing.
The presidential primaries and caucuses are a dynamic
process. Unlike virtually every other election that pollsters ask about, the
selection of presidential nominees does not occur on a single election day. Rather,
the nominating process consists of a series of statewide primaries and caucuses
that plays out over the first few months of every presidential election year.
Here is the critical point: A few early primaries,
especially the Iowa caucuses and the New Hampshire primary,
play a huge role in influencing voter preferences in the states whose primaries
and caucuses follow.
Go back and read that last sentence again, because the basic
idea is hard to overstate, especially in years (like 2008) without an incumbent
president seeking reelection. Moreover, since the outcome of the Iowa caucuses and New
Hampshire primary tend to reshuffle voter
preferences, they can render the "standings" of earlier horse race polling more
or less moot.
Over the next few posts of this series, I will try to
provide some data to demonstrate the influence of those events and how they
often cause a significant reshuffling of voter preferences.
For today, consider the last Democratic nomination battle in
2004, which produced one of the most dramatic shifts. Fortunately, for those of
us who obsess about such things, we have an incredible resource in the National
Annenberg Election Study (NAES), which
conducted a rolling tracking survey from October 2003 through November 2004. Kate Kenski, now an
assistant professor at the University
of Arizona, complied over
7,000 interviews conducted among respondents who were planning to vote in the
Democratic presidential primaries and caucuses in 2004 and prepared the
following graphic:
As the chart makes clear, the Iowa
caucuses and New Hampshire
primary turned the 2004 Democratic contest upside-down. Just before Iowa, according to the
ANES data, only 9% of those planning to vote in the Democratic primaries or
caucuses nationally supported Kerry. Kerry shot up after his Iowa
caucus victory, approaching 50% in the week before New Hampshire and hitting 68% by the end of
February. At the same time, Howard Dean's support collapsed, falling from 31%
in early January to near zero by March, while John Edwards, who finished a
surprisingly strong second in Iowa,
saw his national support grow from 5% to 25%.
Kenski's analysis (which she presented at the 2004 meeting
of the American Political Science Association) indicates that the impact of Iowa and New
Hampshire that year had less to do with increased name
recognition and more with changing voter evaluations of the candidates. Nationally,
Kerry experienced a name recognition gain of roughly ten percentage points nationally
after Iowa,
but he was already known to more than 80% of Democratic primary voters
beforehand. Kenski's analysis showed more dramatic shifts in voter ratings of Kerry and Dean. In other
words, voters who already knew the candidates changed their minds about them
after Iowa and New Hampshire. The NAES surveys also showed
a dramatic shift in perceptions of Kerry and Dean's chances, respectively, of winning
the Democratic nomination that neatly paralleled shifts in voter preference.
The 2004 Democratic race - as illustrated by the NAES data -
is arguably one of the most dramatic examples of a phenomenon typical in the
presidential primary season. Those who win early contests get a boost that
helps them in subsequent contests. Those who study primary elections may disagree
about the reasons for that "momentum" (see this review
just last Sunday by the Boston Globe's
Drake Bennett), but my sense is that it is more than just a blind "bandwagon"
effect. Here are two reasons the early primaries shake up the race:
First, they effectively winnow the field. While news
accounts may emphasize the large field of candidates before the early primaries
(with an emphasis on front-runners), the coverage afterwards focuses far more
intensely on the early winners. The result is that also-ran candidates either
drop out entirely, or effectively drop out of site, a process that simplifies voter
choices. If a voter had been torn between two candidates, and one of those
candidates wins an early primary while the other finishes far back in the pack,
that voter's decision gets much easier.
Second, and probably far more important, the horse race
nature of the coverage leads voters to more positive evaluations of the winners
and more negative evaluations of the losers. Media accounts portray the winners
and their campaigns as competent and able, while the losers look hapless and
faltering. Which set of characteristics would you want in a president? Not
surprisingly, voters readily make the connection between winning and
competence.
Either way, the implication is that the current horse-race
preference numbers are not particularly meaningful as predictors of the
outcome. An early loss is not necessarily fatal. Many early front runners
(Reagan, Mondale, Clinton, both Bushes) have lost early primaries and bounced
back to win their nominations, but the early primaries almost always change
voter preferences.
So what effect will the especially "front-loaded" primary
calendar have in 2008? I'll take that up in the next installment.