Nan Hunter

Polls consistently overestimate voter support for marriage equality

Filed By Nan Hunter | June 16, 2010 3:00 PM | comments

Filed in: Marriage Equality, Politics
Tags: gay marriage, marriage equality, marriage politics, Patrick Egan, Polling, Prop 8, Prop. 8, same-sex marriage

NYU Political Science Professor Patrick Egan has studied 10 years worth of public opinion polling conducted during election campaigns involving same-sex marriage ballot questions, and has found in a new poll on same-sex marriage ballot measures [pdf] that such polls (even those conducted just before election day) consistently overestimate USA_ballot_box.jpgvoter support for gay marriage. Comparing pre-election polls with the election results, Professor Egan concluded that the level of opposition to gay marriage reported in polls tended to be accurate, but that there was typically a 7 point shortfall between expressed support for equal marriage rights and election day results.

Takeaway: Because pollsters create a bottom line prediction by allocating the "undecided's" in the same proportion as the "decided's," polls have consistently overestimated the number of voters who support marriage equality, by an average of 3 percent.

Put another way, either a chunk of voters tell pollsters they will support marriage rights but then don't, or essentially all of the undecided's vote against marriage equality. The study's significance lies in the repetition of this finding - across 10 years of rapidly changing public opinion and 28 different states from Maine to Alaska and Hawaii. Most of the polls analyzed involved proposals allowing amendment of the state's constitution to ban same-sex marriage, now adopted by voters in 30 states.

Professor Egan rejects what seems the most obvious explanation for the gap: the "Bradley effect," in which voters hesitate to admit that they intend to vote in a biased way and profess an intention to vote otherwise, but then do not. (The name references former LA Mayor Tom Bradley, who "won" the exit polls in his 1982 CA gubernatorial race but lost the actual election; Bradley, now deceased, was African-American.) Egan found no difference in polls about gay marriage between those conducted by a human interviewer and those conducted by automated systems, thus discounting the Bradley effect as the cause of the differential.

Professor Egan told a press conference hosted by the Haas Jr. Foundation, which funded the study, that it was impossible to know without further investigation why the discrepancy occurred. He suggested that it might be because opinion polls during campaigns screen for "likely voters," and that those screens might operate in a way to filter out more voters opposing same-sex marriage than voters supporting it. Or, it might be that for this issue, voters who say they are undecided almost all vote the same way in the end: to enact bans on gay marriage. The latter explanation would be odd, he said, because if true, data show that the phenomenon that "undecided = opposition to marriage equality" does not fluctuate throughout the course of the campaign.

Another finding drawing much attention was that neither side's advertising appears to have a significant effect on voting patterns. Professor Egan pointed out that this finding does not indicate what would have happened in the various campaigns had one side done no advertising. However, it does cast big doubt on the arguments among LGBT advocates about which kinds of ads (showing gay families, not showing gay families, etc.) have greater impact during a campaign. Apparently, neither the content nor even the ad campaigns as a whole, for either side, ended up producing any significant effect on changing voter attitudes.

Equality California ED Geoff Kors summed up the lesson for future elections, specifically in the context of repealing Prop 8: "Before we go back to the voters, we need to see solid majority support. Having 49% or 50% support is not enough."

Professor Egan's database included 167 surveys conducted in reference to 32 ballot measures - 30 involving marriage and two related to domestic partnership laws. The database included the No on 8 campaign's internal polls from the 2008 election.

For the first time in many years, there will be no ballot initiatives regarding same-sex marriage or domestic partnership in this year's election.

(Cross-posted at hunter of justice)


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I believe Professor Egan ignores voter turnout dynamics. A poll is only accurate before turnout is factored in. People may tell a pollster their belief or even intended vote, but that doesn't mean they will actually vote. (I didn't see that in his research).

Conservatives are much more likely to actually vote than moderates or liberals. That may explain the differences - it was a factor in Maine. This will be demonstrated this November when the churches will "get out the vote." The LGBT Community hasn't discovered a way to counter that by inspiring our supporters to turn out.

As someone who has long been on the unpopular side of contentious political fights (including gay marriage, which I'm opposed to as a focus of the "movement"), I'm the last one to advocate that anyone should stop fighting for a cause just because it's not popular. Or because there aren't enough votes for it. BUT...this is a deeply revealing study.

And I have no doubt that the findings will be attributed to homophobia. But here's a different hypothesis: Perhaps, just perhaps, there are actually many, straight and queer, who simply don’t think that marriage should be the guarantor of basic rights? You know more about this kind of data interpretation than I do, Nan, but is there a possibility that there's an overly simplistic assumption on the part of many that opposition to gay marriage = homophobia? I think I see a glimmer of that supposition in here, but I'm still looking at this more closely.

The public discussions around gay marriage are also getting more complex and nuanced - I don't think it's going to be easy to sell the "if you love/support gay people, you'll be for gay marriage" line for too long. And marriage may not end, but its status as the essential guarantor of basic benefits may slowly be chipped away. At some point, people are going to ask questions that my compadres and I have been asking for a long time: "If you could get all the benefits of marriage, would you still want marriage? Why? And what do you have to say about the fact that fewer straight people want or need marriage?" And so on.

I don't think the GM movement has adequately prepared for this eventuality.

So where do we go from here? Other than needing higher polling numbers before we take a measure to the ballot box, what else is a takeaway?

This makes a lot of sense, especially after we all saw how Question 1 in Maine went down. After they ran a much more competent campaign than California did, in a less religious state a year later where they outspent the religious right, they still lost. It makes you think people are already decided about this issue. It's not like voters have never heard of it before or that it's so complicated they can be easily confused.

It's turn-out Alex. Maine was an off-day election and the Churches got out the vote - all 1800 of them. We have gay bars - 11 of them in Maine - and they're not exactly church-like.

Even when we poll ahead we don't inspire enough people to make it to the polls. Churches do. Heaven and Hell are very effective.

That will change soon.