How do US political polls work?

So I see from another thread that more than half of republicans think that Obama is a Muslim

This is honesly inconceivable stupidity to me. I am sure that the pollsters must be up to something. How do these things work in general? Is it push polling or what? Are there any voluntary codes or similar that reputable pollsters work to?

From what I have seen it is closer to 20%

As far as how the polls are conducted - it varies from organization to organization - and how the question is phrased. But phrasing of questions are more likely to effect how someone answers questions like - “are you for the death tax?” vs “are you for the estate tax?” vs “do you think it is fair to be taxed when you die?”

Whether someone thinks Obama is a Muslim or not - I think the wording wouldn’t matter that much.

One in five doesn’t surprise me at all - I know people that believe this - I know people that think he is “the Antichrist”. When you really think about it - the fact that we elected a black man named Barack Hussein Obama is amazing (based on the irrational fears of a large percentage of Americans). Keep in mind 33% don’t know Romney is a Mormon and 44% say they don’t know Obama’s religion - some people really don’t follow the news.

They work the same way they do everywhere else: The pollster calls up a bunch of people, in as unbiased a way as they can manage, and ask them a bunch of questions. If they ask both “What political party do you identify with?”, and “What religion is President Obama?”, then they can see what percentage of Republicans believe he’s a Muslim. The data you get from such polls tells you not about the pollsters, but about real American people.

The wording can make a huge difference, as can the the format of the poll. In this case the question could be something like “Do you think Obama is a Muslim”, with options “Definitely”, “Possibly”, “Not Sure”, “Probably Not”, and “Definitely Not”. The results of the poll can be reported as the total of all people who didn’t answer “Definitely Not”. Many polls are push polls designed to elicit specific responses, or even introduce a concept to the polled group. Some number of people asked this question originally didn’t ever think about Obama’s religion until they were polled.

Of course, any reputable pollster will at least publish the wording of their questions along with the results, so you can detect that sort of thing relatively easily.

That is an important point. I’m not sure ‘reputable’ is precise description, but many of the poll results presented by the media are deliberately designed to produce a polarizing result. The politicians themselves, and predictors of elections spend a lot of time analyzing trends based on a series of carefully constructed polls to make determinations. Even a reputable pollster can get outlying results from any one poll.