In partnership with Asian American Decisions and Latino Decisions, the African American Research Collaborative completed 9,400 interviews with black, Latino, AAPI, Native, and white registered voters who had already voted early, or were certain to vote in the November 6, 2018 general election.
Interviews were conducted through a combination of cell phone and landline telephone with live callers and self-completed online. Latino and AAPI voters were given an opportunity to complete their interview in their language of choice at the start of the interview. Respondents were randomly selected from a statewide, or districtwide sample frame, giving all voters an equal opportunity to be selected for interviews. Respondents were reached on landline and cell phone-only households, from October 31 to November 5, 2018 and interviews averaged 14 minutes in length.
Voters were pre-screened based on their vote history in previous midterm elections, and date of registration to include a mix of new registrants and first-time voters as well as those who had confirmed vote history in 2010 and 2014 midterms, or newer voters who first voted in 2016 and even newer registrants who were first-time voters in 2018. Respondents were asked if they had already voted early, and if not, if they were 100% certain they would vote on November 6th, and approximately half of voters indicated they had already voted early, while half were Election Day precinct voters. The interview for any respondent who was not certain was terminated. Using this same methodology in 2014, 92% of the interviewed sample was subsequently confirmed (validated) as having voted when examining official vote records, with no meaningful deviation from reported totals.
For individual states, a minimum of 400 interviews were completed to provide state-specific reliable estimates and carry an overall margin of error of 4.9% for each racial group. For the 70-district congressional district battleground sample, 600 total interviews were conducted per each racial group for a total of 2,400 interviews. Native American voters were selected from a nationwide sample frame and include 600 total interviews. Final data were compared to known census estimates for demographic profiles of voters and weighted to be representative within each state or congressional district.