<b>EXTREMA DIREITA, NEGACIONISMO E A CRISE DA DEMOCRACIA CONSTITUCIONAL: DESAFIOS CONTEMPORÂNEOS PARA OS DIREITOS HUMANOS E O ESTADO DE DIREITO</b>

This article examines the rise of far-right movements and denialism in the contemporary world, analyzing their structural impact on constitutional democracy, human rights, and the epistemic authority of public institutions. Findings indicate that these phenomena combine systematic disinformation, historical revisionism, and attacks on oversight institutions, producing environments of democratic erosion. Hannah Arendt warned that authoritarian regimes are sustained “not only by violence, but by the deliberate destruction of truth criteria” (Arendt, 1973). Similarly, Levitsky and Ziblatt argue that democracies no longer collapse through classic coups but instead “die slowly from within, corroded by leaders who subvert norms, attack the press, and weaken courts” (Levitsky; Ziblatt, 2018). In Brazil, recent episodes of pandemic denialism, attacks on the electoral process, disinformation campaigns, and anti-democratic mobilization reveal patterns similar to those of contemporary illiberal democracies. The Inter-American Court of Human Rights has repeatedly held that denying serious historical facts and disseminating discourse that undermines public trust constitutes a violation of democratic order. Brazil’s Federal Supreme Court affirms that freedom of expression does not protect speech aimed at destroying the constitutional regime. The study concludes that confronting denialism and extremism requires strengthening institutions, promoting civic education, and ensuring responsible information flows.