Commentary: Party Affiliation: What It Is And What It Isn't
These assertions reflect fundamental misunderstanding of party affiliation and how it is measured by polling organizations. Party affiliation is derived from a question typically found at the end of a survey questionnaire, in which respondents are asked how they regard themselves in politics at the moment. In Pew Research Center surveys, the question asks: “In politics today, do you consider yourself a Republican, Democrat or Independent?”
This question is not intended to measure how respondents are registered, how they have voted in the past, or how they have thought of themselves throughout most of their lives. Like most other questions on public opinion surveys, it is intended to measure current feelings about politics – in this case, their feelings of affiliation or disaffection with the major political parties.
Given that it is an attitude and not a personal characteristic, it is not at all comparable to race, ethnicity, gender, age, education, or other demographic markers that are routinely used to check on the representativeness of surveys. Further, long-term tracking and analysis of party identification finds that, for a number of reasons, it varies a good deal from survey to survey. . .