Articles and Analysis


Moore: USA Today's Cluster Analysis of Voters - How Useful?

Topics: 2008 , David Moore , UNH Survey Center , USA Today

Today's Guest Pollster article comes from David W. Moore, a senior fellow with the Carsey Institute at the University of New Hampshire. He is a former vice president and senior editor with the Gallup Poll, where he worked for 13 years, and is the founder and former director of the UNH Survey Center. He manages the blogsite, Skeptical Pollster.com.

On Thursday, July 10, USA Today published an analysis of voter intentions that produced "six types of voters" who the paper claims "will decide the presidential election." The types included: true believers (30 percent of the electorate), up for grabs (18 percent), decided but dissatisfied (16 percent), fired up and favorable (14 percent), firmly decided (12 percent), and skeptical and downbeat (12 percent).* As Mark Blumenthal indicated, this is a fascinating analysis, but how useful is it for understanding the election?

The six types of voters were produced using cluster analysis. This statistical technique is similar to factor analysis, except that it classifies respondents into distinctive groups, while factor analysis classifies various opinions into distinctive groups. Without going into the details of how the technique works, I think it's sufficient to note that the analyst has a great deal of control over the types of groups produced by cluster analysis. The analyst chooses the variables that are used to classify respondents, and also determines how many groups the cluster analysis produces. The fact that the analyst chose six clusters, instead of any other number between two and ten, was purely a subjective decision.

What is most surprising about the analysis is that it is issue free. The stereotypical complaint by political observers about the news media is that reporters focus on the horserace almost to the exclusion of any real substantive issues. This USA Today analysis fits that criticism to a T. I believe there is a widespread consensus among political observers these days that the war in Iraq (and national security more generally), the economy, and healthcare are among the most salient issues dividing the two major presidential candidates. Yet, there is nothing in the newspaper's analysis that groups voters according to their views on any of these major issues. Nor is there any mention of party identification, which often acts as a catch-all variable for a host of issues.

The variables chosen to classify respondents were 1) respondents' enthusiasm about the election, 2) whether respondents think the election would make a difference to them, 3) respondents' opinions (favorable or unfavorable) of each of the two major candidates, and 4) how certain respondents were to vote for the candidate of their choice. As these variable make clear, the classification scheme focuses almost exclusively on election turnout factors, with no mention of issues. Even the favorability ratings can be considered turnout variables in this context, because voters who are negative about both candidates are least likely to vote, while those who are positive about both candidates are mostly likely to vote. This is not to say that a mostly horserace-driven analysis, as this one is, doesn't provide some insights into the electorate. There are many different angles from which to analyze the electorate, and this is certainly a valid one. To me, it's just not as interesting as one that is more political in context.

Like most political junkies, I find intriguing almost any statistical analysis of polling data that goes beyond the simple marginals, and USA Today should be congratulated for making the effort. Still, I'd like to see a little more politics thrown into the mix - even if only to take these six types and describe their party identification, as well as their responses to other public policy questions. But mostly I would like to see a completely new cluster analysis that included policy attitudes as the defining variables for the groups. This is not to say that issues alone will determine the election. But I don't think we can get a good read on the electorate, and which types of voters will ultimately "decide the election," if we ignore issues altogether.

* The percentages exceed 100 percent because of rounding error.


Nick Panagakis:

David is absolutely correct. The USA Today analysis is way short on number of variables to fully describe voter segments and their support for candidates.

In some ways, 1992 was similar to 2008, economic anxiety and a war in Iraq although the outcome was generally considered successful by the public. In 1992, we did two cluster studies in February and September in Illinois, a bellwether then, using discriminant scoring with 30 attitude statements, too numerous to list here. Issues covered are evident in the segment descriptions below.

Here is a brief summary of six segments we identified in 1992.


This is the group which considered themselves to be conservative, socially and on tax issues. They gave 67% and 63% of their votes to Bush and Reagan in prior elections.
In February, they were split on whether Bush should be re-elected, 44% to 43% but gave him 50% or more against the Democratic field of candidates then.
George Bush is still ahead but support has now declined, from 54% in February to 46% in the current poll. More Bush voters have become undecided than Clinton voters who now would get 33% of their vote.
They are divided on which candidate is best for solving economic problems; 30% choose Bush, 27% choose Clinton.
They trust Bush more than Clinton to run the country, 47% to 25%.
They trust Bush more to handle an international crisis, 60% vs. 16% for Clinton.
40% think Bush has a higher standard of conduct and ethics vs. 17% for Clinton.
They are unique from other segments by having low confidence in both Clinton and Bush in solving economic problems; i.e., little or no confidence in Bush 53% and Clinton 45%.


This segment has increased from 13% of Illinois voters to 18%.
This segment is very liberal on the issues. They were the best educated of the segments and had high incomes. They were more supportive than other segments of Democratic presidential candidates in past elections, 67% for Dukakis and 57% for Mondale.
In February, they opposed the re-election of George Bush, 74% to 14%.
Support for Bush is down to 6% from 20%; Clinton is up 19 points to 83%.
They choose Clinton over Bush on all of the attributes by wide margins.
81% have very much or some confidence in Clinton's ability to solve the nation's economic problems.


This segment is very Republican (59%), conservative (66%), and wealthy; i.e., 30% of employed earn over $65,000 and 43% say that is more than enough so they can save some money and buy some extras.
Republican presidential candidates swept this segment before, Bush with 91% and Reagan 87%.
In February, they favored Bush's re-election by 70% to 15% and approved of the job he was doing by 55% to 39%. 74%-83% would have vote for Bush over all possible Democratic candidates then.
This segment has not changed significantly in size, from 23% to 21%.
Their preference in candidates has not changed. 76% would vote for Bush and 69% of these voters have made up their minds.
This segment chooses Bush over Clinton on all attributes; e.g.., 86% to handle an international crisis, higher standard of conduct and ethics, 68%.
75% have very much or some confidence in Bush's ability to solve the nation's economic problems.


This group have the lowest incomes, 45% under $35,000. More say that's not enough to meet their bills and obligations, 26%. And, 69% say it's impossible to make ends meet, 72% to save money and 71% are financially worse off than four years ago.
Half or more gave their votes to Dukakis and Mondale in past elections.
In February, they would have given 52%-62% of their votes to all Democratic candidates over Bush.
Since February, 10% have switched from Bush to Clinton, ahead now by 72% to 10%.
They choose Clinton over Bush on all of the attributes by wide margins.
70% have very much or some confidence in Clinton's ability to solve the nation's economic problems.


This was the youngest segment, many boomers. A majority had voted for Bush and for Reagan, 58% and 53%.
In February, a majority opposed the re-election of George Bush, by 52% to 32%.
Bush suffers his sharpest decline here, down 17 points to 22%. Clinton is up 10 points to 58%.
Bush has a higher standard of conduct and ethics (36% to 19%) and in the event of international crisis (55% to 18%)
Clinton is better on economic problems (40% to 15%), trust in running the country (44% to 29%) and discussing issues which matter most (56% to 14%).


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