Voters who believe that the nation's economy has been worsening are more inclined to vote against the incumbent president than are those who believe it has not been getting worse. This relationship could be present because voters condition their support for the incumbents upon their perceptions of the economy, or, alternatively, because they condition their perceptions of the economy upon their underlying, partisan-based support of the incumbents. If the latter, economic perceptions in mass publics would be more a function of partisan rationalization than of the actual performance of the economy. However, the analyses reported here, based upon a pooled sample of respondents interviewed by the American National Election Studies between 1968 and 2008, provide strong evidence of the former scenario, not the latter. Perceptions of economic trends clearly and accurately track actual changes in GDP and unemployment. Bias due to partisanship is minor.