So what happened?
A new study suggests that polls routinely understate the opposition to marriage equality. They are pretty accurate on the support, but the opposition is more than recorded. Moreover, the opinions are pretty firm, and do not change appreciably during the campaign.
NYU political scientist Patrick Egan studied 167 polls in 33 states with marriage bans over a 10 year period, and compared it to the election results. (PDF here)
- Those favoring and opposing the ballot measures have largely fought to a draw, in that the share of the public saying they intend to vote for or against these measures typically changes very little over the course of these campaigns. Neither side has been more successful than the other on average at changing voter sentiment between the beginning and the end of a campaign.
- Nevertheless, survey data consistently underestimate voter opposition to legal recognition of samesex couples. The share of voters in pre‐election surveys saying they will vote to ban same‐sex marriage is typically seven percentage points lower than the actual vote on election day. By contrast, survey estimates of the proportion of voters intending to vote against same‐sex marriage bans tend to be relatively accurate predictors of the ultimate share of “no” votes.
- Voter surveys do not become appreciably more accurate as election day approaches, meaning that even those polls conducted in a campaign’s final weeks understate the true share of the vote against legal recognition of same‐sex couples. Support for a ban on samesex marriage projected from final polling typically falls three percentage points short of actual results.
- No support is found for two reasons—social desirability bias and voter confusion– typically offered to explain the gap between surveys and election results. There is no immediate evidence indicating that the discrepancies are caused either by poll respondents’ reluctance to express anti‐gay sentiment to survey researchers or respondents’ confusion about the meaning of a “yes” and “no” vote.
But what this means is that the election is basically won or lost before we start. We have to change hearts and minds BEFORE we start the campaign. And that means delaying the campaign until we have done the groundwork, to lay in that solid level of support. And the only way to tell that is, well, polling.