Contested Liberalisms in Mexico: Popular Liberalism, the Fourth Transformation, and the Struggle over Constitutional Identity

Mexico's Cuarta Transformación (4T) is usually read as one instance of a global illiberal turn. This article argues instead that the Mexican constitutional conflict is internal to the liberal-republican tradition: rival projects each claim the mantle of liberalism to define who counts as 'the people'. Drawing on scholarship on popular and plebeian liberalism in Spanish America, it shows that the 4T advances by appropriating a popular, Juarista liberalism against a proprietary one it codes as neoporfirista. Four frameworks — comparative law, legitimation theory, alterity and imagined communities — are applied to presidential discourse, three constitutional reforms and political cartoons, and synthesised through a Constitutional Legitimacy Vector (CLV). The appropriation reconfigures who counts as 'the people' and why citizens obey, producing a structural decoupling resistant to procedural resolution. The case refines the theory of illiberalism: Latin American populism can operate through appropriation of the liberal lineage, not its negation.