Weighting survey data based on social background characteristics such as age, education, gender, and race is a standard practice in public opinion polling. By adjusting the composition of their samples to conform to known demographic characteristics of the population, pollsters greatly increase the accuracy of their results. However, with the exception of the Zogby Poll, most major polling organizations, including the Gallup Poll, have strongly opposed weighting their data based on party identification. This opposition is understandable. Party identification is not a fixed characteristic of the electorate. It is a political attitude that can vary over time. As a result, most pollsters believe that there is no way of accurately determining the underlying distribution of party identification in the population for weighting purposes.