Explaining Politics, Not Polls: Reexamining Macropartisanship with Recalibrated NES Data

Abstract

Like all surveys, the American National Election Studies (NES) imperfectly reflects population characteristics. There are well- known differences between actual and NES-reported turnout rates and between actual and NES-reported presidential vote divisions. This re- search seeks to determine whether the aggregate misrepresentation of turnout and vote choice affects the aggregate measurement of party identification: macropartisanship. After NES data are reweighted to cor- rect for turnout and vote choice errors, macropartisanship is found to be more stable, to be less sensitive to short-term political conditions, and to have shifted more in the Republican direction in the early 1980s. The strength of partisanship also declined a bit more in the 1970s and re- bounded a bit less in recent years than the uncorrected NES data indicate. According to the American National Election Studies (NES), 77.6 percent of eligible Americans turned out to vote in the 2008 presidential election. Barack Obama received 54.8 percent to John McCain's 45.2 percent of the two-party popular vote. This is what the NES data indicate, but this is not what hap- pened. By our best counts, turnout was 61.7 percent of the voting-eligible population, Obama received 53.7 percent, and McCain received 46.3 percent of the two-party popular vote. Despite inaccuracies of this sort, the NES remains the gold standard of survey data to scholars of American elections. NES data are routinely reported