When personality psychologists examine political behaviour, including voting, they usually focus on a narrow range of variables, thereby undermining the breadth of our knowledge. We asked 280 participants who they voted for (or would have) in the 2020 US presidential election and inquired as to their ‘dark’ personality (i.e., psychopathy, sadism, narcissism, and Machiavellianism) and ‘light’ (i.e., Kantianism, humanism, and faith in humanity) personality traits, political attitudes (i.e., social dominance orientation, right-wing authoritarianism, and left-wing authoritarianism), and how many times people chose each of the six moral foundations (i.e., care, fairness, loyalty, purity, liberty, and hierarchy). We found that personality traits (as distal systems) were negligibly important in presidential choice, moral choices (as parallel-yet-related choices) had some utility especially in relation to voting for a third-party candidate, and political attitudes (as proximal predictors) had the broadest and strongest associations. In addition, we found that third-party voters showed stronger concerns for purity than Biden supporters, and greater concerns for fairness than Trump supporters. Our results focus on how dispositional measures can add to standard sociodemographic predictors used by pollsters, politicians, and pundits.