A venerable supposition of American survey research is that the vast majority of voters have incoherent and unstable preferences about political issues, which in turn have little impact on vote choice. We demonstrate that these findings are manifestations of measurement error associated with individual survey items. First, we show that averaging a large number of survey items on the same broadly defined issue area—for example, government involvement in the economy, or moral issues—eliminates a large amount of measurement error and reveals issue preferences that are well structured and stable. This stability increases steadily as the number of survey items increases and can approach that of party identification. Second, we show that once measurement error has been reduced through the use of multiple measures, issue preferences have much greater explanatory power in models of presidential vote choice, again approaching that of party identification.