From the thesis: "This thesis examines how foreign and domestic disinformation threatens American democracy and security. Unlike inadvertent misinformation, disinformation involves intentionally false content meant to cause harm. Current academic models provide critical insight into the coordinated processes that systematically undermine institutions, distort understanding, and sow division, as seen on January 6. Such insidious democratic backsliding and information warfare indicate an urgent need to defend democratic principles against disinformation's dangers. This thesis uses an evaluative paradigm of comparative analysis in three steps. The first step involves applying definitions and frameworks to assess disinformation campaigns. The next step establishes the indicators of a functioning democracy. The final step involves examining the incidence of democratic erosion and its consequences. Then, based on this inquiry's findings, this thesis offers a comparative analysis of three disinformation campaigns: Pizzagate, Brexit, and the Big Steal. This thesis concludes that examining the intersection of inequality and polarization, formulating countermeasures, and anticipating psychosocial impacts can provide a comprehensive understanding of contemporary democracy's challenges and a path forward. The vigilant safeguarding of America's democratic foundations is critical amid disinformation's complex threats."