Voting Behavior Study 3 – Global Warming And the 2010 Congressional Midterm Elections

The 2010 congressional elections occurred midway through President Barack Obama’s first term in office, offering the electorate its first opportunity to weigh in on the direction of the country since his historic ascent to the White House. The country was struggling with recession-driven unemployment, and Obama and congressional Democrats had pushed through a major health care program. The Tea Party political movement was gaining steam and played a role in supporting and opposing candidates.

In addition to economic concerns that preoccupied the nation leading up to the election, global warming was one of a suite of issues that some candidates mentioned or included on their campaign websites. Did their views on this issue influence the way people voted?

When the ballots were counted, Democrats suffered major losses, and the House of Representatives returned to Republican control. In the Senate, the Republicans enlarged their majority by gaining six seats.

To determine whether taking positions on global warming helped or hindered candidates’ chances of victory, this study analyzed candidate websites in 430 House and Senate races. (The study did not consider races where an incumbent ran unopposed in the general election.)

Based on the website content, the candidate was labelled “green” if he/she acknowledged the existence or human cause of global warming or endorsed the need for government actions, and also did not make any “not-green” statements.

Candidates were labelled “not-green” if they made statements at odds with those green sentiments and did not make green statements. They were labelled “mixed” if they made statements on both sides of the issue, and “silent” if they did not address the topic at all.

The analysis revealed that taking the “green” position–stating belief in human-caused global warming and voicing support for government action –helps candidates win elections.

Research details

A majority of Democratic candidates in both House and Senate contests were “green”, while a majority of Republicans was either “silent” or “mixed” on global warming, as shown in the figure below.


Where Democrats were “silent” on global warming — saying nothing about it one way or the other — they won 17% of the races. Republicans who were “silent” won 83%. When the race featured a candidate openly talking about global warming, the following happened, as shown in the figure below:

  • Democrats won 69% of the races when they took a “green” position and their Republican opponents remained “silent” or voiced skepticism.
  • Democrats won 68% of the races when the Democrat was “green” and the Republican was “not-green”.
  • Republicans won 82% of the contests when the Democrat and Republican were both “green”.
  • Republicans won about 96% of the races when the Democrat was “silent” on the issue and the Republican was “not-green”.
  • Republicans won 100% of the races when the Republican was “green” on the issue and the Democrat remained “silent”.

Thus, when Republican opponents were “silent”/”mixed” or took a “not-green” position, Democrats were much more likely to win by being “green” on global warming than if they were “silent”/”mixed”.  When Democratic candidates were “silent”/”mixed”, Republicans were more likely to win with a “green” or “not-green” position than if they were “silent”/”mixed”.