The democratic backsliding literature sees reactionary shifts among the electorates of mature democracies as a reason for the rise of right-wing populism (RWP)—shifts that supposedly fuel citizens’ distrust in democratic institutions and their readiness to support RWP in its efforts to cut back on democracy’s liberal principles. However, the assumptions underlying this democracy falling narrative are more often stated than tested. Filling this void, we analyze data from the European Values Study/World Values Surveys in a cross-national longitudinal design amended by multilevel evidence, covering all EU countries surveyed at two distant timepoints over the past twenty to twenty-five years. We test whether reactionary shifts among socio-economically vulnerable electoral segments increased polarization over four ideological cleavages: right-vs-left on economic issues, nativism-vs-cosmopolitanism on immigration issues, patriarchy-vs-emancipation on sexuality issues, and economy-vs-environment on sustainability issues. Specifically, we examine whether those population segments at the reactionary end of these cleavages lost trust in democracies’ political institutions and their liberal principles in ways that increase voters’ readiness to support RWP parties. Our results provide no confirmation that polarizing shifts in the population account for RWP’s electoral rise. We conclude that the problems explaining RWP success do not originate in reactionary public opinion shifts. Instead, we propose further research into potential representation gaps with respect to nonvoter camps that grew larger during the pre-RWP era and are now mobilized by RWP parties—a game change presumably triggered by the rise of social media.