Polling: a look inside the machinery of public opinion surveys

Last summer, when the GOP nomination contest got rolling, a Gallup poll also showed that 18 percent would not vote for a Mormon for president. So Romney's selection as the nominee hasn't moved the bar.

On the other hand, perhaps that's because the candidate hasn't talked about his faith much on the trail, Newport says. The flip side of this calculation is that the June survey showed approximately 4 in 10 of those polled don't know that Romney is Mormon.

The results of the religion question produced a spate of stories that looked at the issue from different angles. USA Today wrote: "Gallup poll: 44% don't know Obama's religion." ABC News took another view: "Americans least likely to vote for atheist, Muslim presidential candidates, polls finds." UPI homed in on Romney's faith: "18% would not vote Mormon," and CNN looked at the historic trend: "Bias against Mormon presidential candidate unchanged since 1967, poll finds."

One other tidbit to consider when evaluating these numbers: In 1960, 21 percent of Americans responded to a similarly framed question about Catholics. And then the nation elected one, John F. Kennedy Jr.

Nuance and framing – both historic and current – is meaningful, then, in determining what polling communicates. And, Newport says, this poll suggests that in terms of the Mormon question: "In context, it's not a deal killer."

The truth test: election results

Pollsters of varying methods ultimately have one very public test: Election Day. Who is right – and how the electorate shapes up – will be indisputably clear.

Reputable outlets, like Gallup, have a track record of results. In its final preelection polls in the 19 presidential contests since 1936, Gallup has incorrectly predicted just three: 1948, 1976, and 2004, in which the final Gallup survey showed a tie between George W. Bush, the winner, and the Democratic nominee John F. Kerry. It's worth noting that Gallup's preelection poll in 2000 gave Mr. Bush the advantage over Democrat Al Gore, and while Bush ultimately won the election, Gore won the popular vote.

For Americans hoping to follow this season's polls on their own, experts say the source of a poll is the best place to start when determining veracity of numbers. Traugott suggests that when evaluating data, citizens seek out not just who conducted the survey, but also its field dates, who was sampled, and what questions were asked, and review the full questionnaire.

And as November nears, perhaps those who answer their phones and let a pollster into their dinner hour can take heart that there are many people – like interviewer Jablonski – with high intentions for accuracy on the other end of the phone.

"If the quality isn't good," he says of his work and Gallup's, "the data isn't going to be good."

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