Survey Methods
Results are based on telephone interviews with 1,007 national adults, aged 18 and older, conducted June 11-14, 2007. For results based on the total sample of national adults, one can say with 95% confidence that the maximum margin of sampling error is ±3 percentage points.
For results based on the sample of 393 Republicans or Republican leaners, the maximum margin of sampling error is ±5 percentage points.
For results based on the sample of 516 Democrats or Democratic leaners, the maximum margin of sampling error is ±5 percentage points.
In addition to sampling error, question wording and practical difficulties in conducting surveys can introduce error or bias into the findings of public opinion polls.
http://www.galluppoll.com/content/?ci=27910
