Isn't Gallops polling so bad anymore they refuse to do Presidential elections?
Results are based on telephone interviews conducted May 3-7, 2017 with a random sample of –1,011—adults, aged 18+, living in all 50 U.S. states and the District of Columbia. For results based on this sample of national adults, the margin of sampling error is ±4 percentage points at the 95% confidence level.
For results based on the sample of –518—national adults in Form A, the margin of sampling error is ±5 percentage points.
For results based on the sample of –493—national adults in Form B, the margins of sampling error is ±5 percentage points.
For results based on the sample of –531-- adults employed full- or part-time, the margin of sampling error is ±5 percentage points.
Interviews are conducted with respondents on landline telephones and cellular phones, with interviews conducted in Spanish for respondents who are primarily Spanish-speaking. Each sample of national adults includes a minimum quota of 70% cell phone respondents and 30% landline respondents, with additional minimum quotas by time zone within region. Landline and cell phone telephone numbers are selected using random digit dial methods. Gallup obtained sample for this study from Survey Sampling International. Landline respondents are chosen at random within each household on the basis of which member has the next birthday.
Samples are weighted to correct for unequal selection probability, non-response, and double coverage of landline and cell users in the two sampling frames. They are also weighted to match the national demographics of gender, age, race, Hispanic ethnicity, education, region, population density, and phone status (cell phone-only/landline only/both and cell phone mostly). Demographic weighting targets are based on the March 2016 Current Population Survey figures for the aged 18 and older U.S. population. Phone status targets are based on the January-June 2016 National Health Interview Survey. Population density targets are based on the 2010 census. All reported margins of sampling error include the computed design effects for weighting.
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. For questions about how this survey was conducted, please contact galluphelp@gallup.com.