In the polarized battle between President Obama and Mitt Romney, arcane shifts in polling techniques can have important consequences for the results -- and public perceptions of the contest.
Bill McInturff, a Republican pollster, and Peter Hart, his Democratic counterpart, who conduct the NBC News/Wall Street Journal poll, proved the point in their latest poll, conducted July 18-22, when they increased the proportion of respondents who rely exclusively on cellphones to 30 percent from 25 percent. To home in on them, the pollsters ended calls answered on cellphones if the respondents said they also had landlines.
Their findings affirmed arguments that "cell only" Americans have significantly different, and more Democratic, political views than those with landlines. Overall, the poll showed Obama leading Romney by 49 percent to 43 percent -- providing a confidence-boosting talking point for Democrats and provoking sharp criticism from Republicans.
Scott Rasmussen, who owns an independent polling firm, approaches the "cell only" problem differently, as he must by law.
His Rasmussen Reports conducts surveys through automated dialing, which under Federal Communications Commission rules is permitted for landlines but not cellphones.
So in Rasmussen's polls, online interviews account for 15 to 20 percent of each survey, which he figures helps him reach the same kinds of voters, especially younger ones, in the "cell only" category. The result he reported the morning of July 25, a few hours after the NBC News/Wall Street Journal poll was released, was strikingly different: Romney had 47 percent, and Obama 44 percent.
"Nobody has the answers," Rasmussen said of different approaches to the issue. "We're all experimenting with the same thing. How do you reach people in a way they communicate?"