When leaders eclipse institutions: the leader–institution trust gap and anti-democratic attitudes in South Korea and the United States

Why do citizens in consolidated democracies tolerate the concentration of executive power at the expense of institutional constraints? This study identifies the leader–institution trust gap, defined as the divergence between trust in a political leader and trust in the institutions constraining executive authority, as an attitudinal correlate of such tolerance. Drawing on the 2025 EAI Polarization Perception Survey, fielded after South Korean President Yoon Suk-yeol's martial-law declaration, and the 2024 ANES Time Series, fielded around the election that returned Donald Trump to the presidency, the analysis shows that citizens with larger trust gaps express stronger anti-democratic attitudes in both countries. In the main specifications, this relationship is strongest among respondents who judge the national economy to be deteriorating. Its partisan profile differs across the two cases: the gap is most closely tied to anti-democratic attitudes among opposition supporters in South Korea and among Republicans in the United States, though the U.S. asymmetry depends in part on how the gap is operationalized. This contrast is consistent with the different ways each leader's challenge to institutions was interpreted politically. The findings identify a configuration of political confidence through which personalization and institutional distrust become linked to tolerance for executive override.