The Crisis from Within: Disinformation, Affective Polarization, and the Erosion of Democratic Constitutionalism in the 21st Century

This essay examines the structural crisis of democratic constitutionalism in the 21st century, arguing that the contemporary threat to democracy does not originate from external forces but from within its own mechanisms. Drawing on political theory, comparative politics, and communication studies, the text traces the historical trajectory of democracy from Cleisthenes to Huntington's third wave and Fukuyama's "end of history," before analyzing how this model has been systematically eroded by populism, disinformation, and affective polarization. The January 6, 2021 attack on the U.S. Capitol and the January 8, 2023 attacks on Brazilian institutions are examined as parallel case studies of how fabricated electoral fraud narratives, algorithmic echo chambers, and deep partisan hostility can translate political dissatisfaction into institutional violence. The essay concludes that the democratic crisis is not primarily institutional, courts have held and mechanisms have functioned, but social and informational: the true foundation of democracy is the population's capacity to inhabit a shared public space, and it is precisely this capacity that disinformation and polarization have eroded.