Partisan polarization in the United States has intensified, fueling hostility toward partisan out-groups and eroding political and social trust. This divide has often been compared to the fervent loyalty of sports fans, where competition and “team spirit” dominate behaviors. Despite this comparison, research has not systematically explored how views on fairness and competitiveness in partisan competition predict support for anti-democratic policies. This paper addresses this gap by developing a novel survey battery that uses sports as a conceptual proxy to measure these attitudes. We test this survey battery, and further refine it, on two U.S. samples. Using dimensional analysis we recover two latent dimensions: fairness and competitiveness. Using a novel measure, a gerrymandering map-choice, we find that these dimensions are highly predictive of anti-democratic behavior. This study illustrates how individuals’ partisanship and underlying psychology lead to undemocratic outcomes in the context of partisan competition.