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Voter Behavior: 8 Studies

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Does The Global Warming Issue Shape Voting?

Voters consider a wide range of factors when evaluating candidates including:

  • Party identification
  • Performance of the incumbent
  • Health of the nation
  • Interests of social groups
  • Perceptions of candidates’ personalities
  • Emotions evoked by candidates
  • Policy positions endorsed by candidates

The ‘Issue Public’

When a person is passionate about a particular issue, he or she is especially likely to use the issue when deciding for whom to vote.  Philip Converse called this small group of citizens the “issue public” for an issue.  The U.S. electorate contains a gun-control issue public, an abortion issue public, and other voter groups focused on their own prioritized policy topics.

The global warming issue public  (people for whom warming is extremely personally important) was 9% of American adults in 1997 and at an all-time high of 25% in 2020.

Percent of Americans who thought global warming is extremely personally important

Most issue publics are divided about equally between people on either side of the issue.  This balance makes it difficult for politicians to gain broad support by talking about those subjects.  If a candidate takes a position on one side, he or she will alienate about as many people as he or she will attract.

The global warming issue public is unusual, because it is overwhelmingly one-sided. The vast majority believe that global warming has been happening, that it is human-caused, that it is a threat, and that it requires government action. A tiny minority of this issue public takes a skeptical view.

Voting and Global Warming

Given this unusual profile, do views on global warming influence voter decisions at the polls? Eight studies conducted over seven years answer this question with a resounding “yes”.

Key findings are:

  • Candidates attract more votes by stating a belief in global warming and its human causes, and they hurt their electoral chances by voicing opposite positions.  Such expressions are most likely to attract votes from Democrats and Independents.
  • Taking a skeptical position about global warming hurts a candidate among Democratic and Independent voters and does not attract votes from Republicans.

Terminology: “Green” and “Not-Green” Beliefs

This website uses the terms “green” and “not-green” to label people’s sets of beliefs about global warming.  A “green” position means believing that global warming has been happening, is human-caused, is threatening, and requires government action. A “not-green” position means believing that global warming has not been happening, is not human caused, is not threatening, and does not merit government action.*

Summaries of each study conducted between 2008 and 2018.

Study 1. The 2008 White House Contest

A survey in late 2008 and 2009 looked into whether the global warming issue affected the presidential election in which Barack Obama competed against John McCain.

Among the global warming issue public, 86% believed that it is occurring and is human-caused, is bad, and requires government action.  Thus, one would expect that the issue would enhance the changes of victory of a candidate who takes a green position and would reduce votes received by skeptical candidates.

Sixty percent of voters in the issue public thought that Mr. Obama endorsed the green view more than did Mr. McCain. As a result, Mr. Obama gained an electoral advantage because the vast majority of high-importance respondents were on the green side of the issue.

Read more information on study 1 methods and results

Study 2. The 2012 White House Race

In June 2012, a nationally representative sample of American adults reported their presidential voting intentions and their thoughts on global warming. This research sought to learn if candidates’ global warming views were a consideration for the electorate, and whether a voter’s own attitudes on the subject influenced how he or she voted. Issue public members were more likely than others to support candidates whom they perceived to share their own views on the subject. A majority of these people said they would vote for Mr. Obama over Mr. Romney. Thus, global warming did matter in that presidential election.

Read more information on study 2 methods and results

Study 3. The 2010 Congressional Midterm Elections

A 2010 study analyzed the campaign and government websites of candidates in 430 House and Senate races to determine which candidates were green, not-green, or silent/mixed on global warming. Election results were analyzed alongside the candidates’ global warming views on websites. The results indicate that Democrats helped themselves electorally by voicing green beliefs about global warming, human causation, or the need for government action, as opposed to remaining silent on the issue. When Republicans expressed similar views and Democrats remained silent, Republicans won 100% of the time.

Read more information on study 3 methods and results

Study 4. The 2012 Presidential Election

In 2011, a nationally representative sample of American adults was interviewed to explore whether respondents’ candidate preferences in the 2012 presidential election were predicted by their views of global warming.

The survey proposed a series of hypothetical match-ups: between Democrat Barack Obama and each of various Republicans, Mitt Romney, Ron Paul, Rick Perry, Jon Huntsman, and Michele Bachmann. Respondents stated their candidate preferences in each of the hypothetical races.

Respondents who said they believed in human-caused global warming were more likely to favor Mr. Obama in the match-ups. More generally, respondents were more likely to vote for the candidate whose views on global warming most closely matched their own.

Read more information on study 4 methods and results

Study 5.  Hypothetical Candidates in 2015

A 2015 survey asked a nationally representative sample of American adults about the likelihood that they would vote for candidates who made varying claims about global warming. The claims presented to them were: that climate change has been occurring and should be addressed, that it is a hoax and should not be addressed, or that the candidate is not a scientist and thus is ill-equipped to make claims about global warming.

Respondents were more likely to favor candidates who viewed global warming as a concern.

Read more information on study 5 methods and results

Study 6. Hypothetical Senatorial Candidates in 2010

A 2010 survey asked a nationally representative sample of adults how likely they were to vote for Senate candidates based on the candidates’ global warming policy stances. Results showed that when a hypothetical candidate talked about global warming as a real issue that needed to be addressed, that candidate gained votes.

Read more information on study 6 methods and results

Study 7. 2010 Hypothetical Senatorial Candidates in Florida, Maine, and Massachusetts

In 2010, in surveys conducted in Florida, Maine, and Massachusetts, respondents were more likely to vote for a candidate who voiced belief in global warming and human causes.

Read more information on study 7 methods and results

Study 8. 2012 Barack Obama vs. Mitt Romney

A 2012, survey respondents were asked about their voting intentions after they watched videos of President Obama and Governor Romney making comments about global warming. Controlling for other factors that people take into account when making voting decisions, the survey found that voters looked more favorably on Mr. Romney when he spoke about the need to address global warming. Mr. Obama gained an advantage only when a respondent watched a video featuring him and not one featuring Mr. Romney.

Read more information on study 8 methods and results

*Note: This does not imply that all Americans fall into either the ‘green’ or ‘not-green’ categories, nor does it imply value judgments. It does not imply that a ‘green’ position is the position of so-called ‘green’ political parties in some counties or the position of environmental activists in the U.S. and elsewhere. We are open to using different terminology if we discover a superior approach.  But in the meantime, use of “green” and “not-green” herein is intended to make no value judgments, nor to accord more respect or legitimacy to one position over the other.

Read the publication for more on these findings