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Report | Religious Voters and California’s Proposition 8


In the November 2008 election, California voters narrowly supported Proposition 8 (52% to 48%), which repealed an existing California law allowing marriage between same-sex couples by amending the state constitution to restrict marriage to heterosexual couples. The role of religion in that vote has been the subject of much interest and debate, but solid data on religion has been scattered. This memo gathers religious data from both the National Election Pool exit polls and a post-election poll by Public Policy Institute of California, including some previously unreleased data, to provide a comprehensive look at the role religion played in the passage of Proposition 8.

Read the full report here.

Religious Affiliation and Support for Proposition 8

There were large differences between religious groups on Proposition 8. The vastProp 8 Relig 246x300 Report | Religious Voters and Californias Proposition 8 majority of white evangelical Protestants supported the ballot measure (88% to 12%). The measure also garnered significant support among Catholics, with Hispanic Catholics supporting Proposition 8 at slightly higher levels than white Catholics (62% to 57% respectively).

White mainline Protestants were significantly more likely to oppose Proposition 8 than any other religious group. They split evenly over the measure (50% to 50%). Californians with no religious preference were overwhelmingly opposed to Proposition 8. Approximately 4-in-5 voted against it.

Intensity Gap between Supporters and Opponents of Proposition 8

While nearly two-thirds (65%) of all voters said that the outcome of the vote on Proposition 8 was very important, there was a significant intensity gap between supporters and opponents for Proposition 8.

White evangelicals, the group most supportive of Proposition 8, were the most likely to say the outcome of the vote on Proposition 8 was very important to them (76%). White mainline Protestants, the religious group most opposed to the measure, were least likely to say it was very important to them (55%).

Competing Frames: Preserving Marriage and Religious Objections vs. Equal Rights and Freedoms

Supporters and opponents also differed in the reasons they gave for their vote in response to an open-ended question. Supporters of Proposition 8 were most likely to cite preserving marriage (63%) or religious objections (16%). Two-thirds of white evangelicals and Catholics (66% and 67% respectively) said preserving marriage was the reason they supported Proposition 8. White evangelicals were somewhat more likely to cite religious objections or negative views about homosexuality as reasons for supporting the measure (20%) than Catholics (13%) or white mainline Protestants (11%).

Among voters who opposed the ballot measure, the overwhelming majority said that their primary reason for opposing the measure was their belief that homosexuals should have the right to marry or should be guaranteed the same freedoms as everyone else. There were few differences by religious affiliation.

Proposition 8 as a Proxy for Same-Sex Marriage

There is evidence that Proposition 8 served as proxy for views on same-sex marriage. Overall, the level of support for same-sex marriage was nearly identical to the percentage of votes for Proposition 8 (47% to 48% respectively). Approximately 9-in-10 (92%) Californians who opposed same-sex marriage also supported Proposition 8, and approximately 9-in-10 (89%) same-sex marriage supporters opposed Proposition 8.

Furthermore, these correlations held across religious groups. For instance, about one-in-ten (12%) white evangelicals support same-sex marriage, and the same number voted against Proposition 8. Similarly, 50% of white mainline Protestants in California support same-sex marriage, and an identical number opposed Proposition 8.

Prop 8 Attend Report | Religious Voters and Californias Proposition 8

Worship Attendance and Proposition 8

The 2008 exit polls found that frequency of religious attendance was strongly correlated with voting on Proposition 8. More than 4-in-5 Californians who attend religious services weekly or more supported Proposition 8. On the other end of the spectrum, less than 1-in-5 (17%) of those who never attend supported the measure.

One group of strategic interest is the large group of religious voters who attend religious services occasionally, a group that comprises nearly half of all Californians (46%). A majority of these religious Californians opposed Proposition 8 (54% to 46%).


Californians remain split over the issue of same-sex marriage, with nearly equal numbers supporting and opposing it (47% to 48% respectively). The high correlation between voters’ support of same-sex marriage and opposition to Proposition 8 suggest that many voters saw Proposition 8 as a referendum on same-sex marriage.

There were clear differences between supporters and opponents, not only how important they perceived the outcome of the measure to be, but in the value frames they brought to the debate. Supporters of Proposition 8 felt more strongly that the outcome of the vote was important, and were driven primarily by the desire to preserve marriage or to act on religious objections to same-sex marriage. Opponents of Proposition 8 felt less strongly about the importance of the vote, and were motivated by the desire to extend equal rights and freedoms to gay and lesbian people. These motivational differences and clashing frames are important for understanding the competing values voters bring to these issues.

This data also cautions against an overly simplistic view of the role of religion in the vote. The passage of Proposition 8 was not simply due to the overwhelming support of religious groups. White evangelical Protestants and Californians who attend religious services weekly or more were strong supporters of Proposition 8. However, half of all white mainline Protestants and the majority of Californians who attend worship services occasionally opposed the measure.

Read the full report here.