Over the past two decades, Latin American democracies have witnessed a structural shift in the nature of regime instability. Rather than succumbing to traditional military coups d'état, democratic systems across the region are increasingly experiencing subtle, incremental processes of executive-led democratic erosion. Elected leaders utilizing populist rhetoric frequently deploy constitutional amendments, judicial packing, and regulatory pressure to weaken horizontal accountability while retaining formal competitive electoral procedures. This paper critically investigates the mechanics of democratic backsliding, populist governance, and institutional resilience across contemporary Latin America, focusing on comparative case dynamics within Mexico, Venezuela, El Salvador, and Brazil. Utilizing a comparative political economy and constitutional framework, this study evaluates how hyper-presidential mandates interact with electoral systems, autonomous oversight bodies, and civil society resistance. The research reveals that formal institutional design alone is insufficient to stem backsliding; rather, systemic resilience depends on the interactive density of autonomous judiciaries, sub-national institutional checks, and independent election management bodies. The paper formulates a normative legal and political framework aimed at fortifying democratic institutions against executive overreach without triggering systemic governance paralysis.