In 2019 at the SPSP Political Psychology Pre-Conference, key stakeholders and researchers were invited to debate the question “does ideological diversity impact the quality of our research?” If Clark and Winegard's (in press) review of ideological epistemology and its significance to social science is mostly on target, it would predict that many at the debate were unconvinced by those arguing that political bias matters. Why? To the extent that social psychologists function as a moral tribal community (as Clark and Winegard argue), motivated to protect their professional and political interests, they will fight tooth and nail to defend their sacred values and professional statuses against charges of political bias. Of course, they might also do so out of a justified belief that they were unfairly accused. How can one tell the difference? In this paper we argue that this can be accomplished by identifying how political biases manifest in social psychology. To that end, we expand upon two of Clark and Winegard's (in press) arguments: 1. there are no reasons to believe that social scientists are immune to the biases, errors, and social processes that can lead to distortions that stem from tribal loyalties; 2. these tribal tendencies, combined with extreme ideological homogeneity, work to create significant problems for the pursuit of scientific truth. Specifically, we present a heuristic model of political bias that identifies ways they manifest, and we review evidence that bears on it.