Where policy polls go awry

By Ezra Klein

I think polls are quite good at telling you the public’s level of support for a particular party or politician, and even level of support for a particular bill or law. But polls tend to really confuse people by also including information on the public’s possible level of support for a particular policy or piece of legislation. Matt Yglesias explains where things go awry:

People focus too much on polls about what “the people” think about “the issues.” What a lot of analysis misses is that (a) many voters aren’t paying attention at all and (b) most voters have stronger opinions about famous politicians than they do about issues. So consider that among self-identified Republicans, getting more education makes you less informed about global warming. But that’s not because Republicans with BAs are ignorant compared to Republicans without them. On the contrary. Republicans with BAs are better informed about what the Republican view is and therefore worse informed about the underlying issue because the Republican position is mistaken.

One common mistake that flows from this is to overrate the relevance of polls showing that the public supports various component pieces of the legislation you favor. You saw this a lot during health-care reform, where the specifics of the law were popular but the law itself was not and liberals took that to mean they had a mere simple communications problem. What those polls really told you was that in a world where the two parties both agreed to support something like the Affordable Care Act, the Affordable Care Act would be extremely popular. But in a world where there was a bitter and endless fight over the Affordable Care Act, the Affordable Care Act wasn’t going to be very popular. Polls that try to gauge support for laws by testing policy preferences are testing a world we don’t actually live in.