Party identification is an important attitude that influences the vote. Most voters identify with one of the two major political parties, and these basic partisan loyalties influence the vote. Party identification normally is measured by asking individuals whether they consider themselves to be a Democrat, Republican, or independent. Those indicating Democratic or Republican are then asked whether they are a strong or a weak Democrat or Republican, while those claiming to be an independent are asked whether they feel closer to one of the two political parties. This yields a sevenfold classification: strong Democrats, weak Democrats, independents closer to the Democrats, independents not closer to either party, independents closer to the Republicans, weak Republicans, and strong Republicans. This seven-point party identification scale is in the dataset.
The direct influence of party identification on the vote is small in presidential elections. Very few voters probably cast a ballot for Bush solely because he was a Republican. But the indirect influence of party identification is great, in that partisan loyalties influence evaluations of candidates, assessments of government performance, and perceptions of political events. Put simply, party identification is a perceptual screen--a pair of partisan-tinted eyeglasses through which the voter views the political world. Party identification may be somewhat less important now than in the past, but it is still a very significant factor for explaining political orientations and behavior (Abramson, Aldrich, and Rhode 2003, 168-191).