Mexico’s 2021 midterm elections occurred amid concerns about the erosion of democratic institutions. Supporters of President López Obrador (AMLO) view his centralization of power in the executive as necessary to make government work for a marginalized majority. But the same state weaknesses that helped to propel AMLO to power constrain his responses to complex governance problems, including poverty and violent crime. This limits AMLO’s ability to consolidate a populist supermajority that can overwhelm constitutional checks and balances. State weakness and his increased reliance on the military thus pose a greater threat to Mexico’s democracy than a new electoral hegemon.