This work explored a rapidly unfolding polarizing issue – Israel’s Judicial Reform, introduced in January 2023. We documented mass polarization over whether the judicial reform presents a threat to democracy and examined its predictors. We found evidence that different types of polarization are related, but distinct constructs. Specifically, issue-based, affective, and perceived societal polarization are differentially predicted by trust in democratic institutions (i.e., government, judiciary, and media), constructive patriotism, and social identity. Constructive patriotism and trust in institutions predicted issue-based and affective polarization, whereas social identity predicted only issue-based polarization. These effects vary across pro- and anti-reform individuals. Perceived societal polarization was predicted by generalized trust and universalism/benevolence values across the polarized camps. These types of polarization differentially predicted downstream consequences of polarization–conflict management attitudes, acts of, and responses to, civil protests, and outgroup attitudes. We discuss the results in the context of growing anti-liberal-democratic movements and the importance of democratic education.