Survey USA has released an interesting look at Bush's Job Approval numbers around the nation. The overall results are predictable, especially when you notice that the polls were taken mostly by television stations. In Rhode Island, for example, Bush has a weak-sounding 23% Job Approval, but the results came from WLNE-TV, who surveyed 600 "adults", with predictable overweighting on the young, Democrats, "Pro-Choice" adults and people who seldom attend church, if ever. On the other end of the spectrum, in Utah KSL-TV took the poll, resulting in 57% Approval in a respondent pool which was heavily Republican and who regularly attend church, but again who tend to be very young, who are not necessarily registered to vote, and which includes a sample of "pro-choice" respondents higher than the demographic norm for Utah.
What we see here is a hint to the method of poll-taking by television stations. The established nominal standard for national poll-taking is known as RDD, for Random Digit Dialed, where people are called randomly and asked identical questions. This is the process Survey USA used, per their Statement of Methodology. I would quibble just a bit, however, about their margin of error. Since each state was polled separately, each is a different poll and so the margin of error for the whole poll must reasonably be the highest MOE for any of the state polls taken, not derived from the total number of respondents nationally, because the poll was managed by fifty-two different groups (Survey USA plus 51 different TV stations), calling into question the constancy of the overall polling. I am not saying the numbers are not valid, but I am simply restricting claims to accuracy to the actual levels of procedure used. And reminding the reader again, to measure polls in their faithfulness to known demographics.