We conducted a longitudinal study involving 734 college students over a three-month period that included the 2008 U.S. presidential election. The study investigated factors such as respondents' personality characteristics and ideological proclivities in predicting perceptions of the major candidates and both stability and change in voting preferences for Barack Obama and John McCain. Previous research on personality and political orientation suggests that Openness to New Experiences is positively associated with liberal political preferences, whereas Conscientiousness is positively associated with conservative preferences; we replicated these results in the context of the current study. Several ideological factors also predicted conversion to Obama's candidacy. These included respondents' degree of self-reported liberalism, perceptions of their parents as liberal (versus conservative), and lower scores on measures of authoritarianism and political system justification (i.e., support for the prevailing system of electoral politics and government). The effects of Openness and Conscientiousness on candidate preferences were statistically mediated by ideological variables, providing further evidence that general predispositions exist that link personality and political orientation, and these are likely to play a significant role in electoral politics. Implications for the integration of “top-down” (institutional) and “bottom-up” (psychological) approaches to the study of political behavior are discussed.