Ralph Ellison’s Invisible Man (1952) was published when the centrism of Cold War liberalism was supplanting the radical, multiethnic working-class collectivism characteristic of the liberal-left Popular Front and New Deal. In 1949, amid sharpening conflicts with the US’s recent ally the Soviet Union, Arthur Schlesinger, Jr.’s spatial trope of the “vital center” redefined the US political landscape to situate, as constitutive of a new liberalism, the extremist affirmation of American national values and institutions against conflated radicalisms of right and left. While Invisible Man is often read as aligned with vital center liberalism – and as declaring African American commitment to its ethos – this chapter recovers the more idiosyncratic and radical theorization of power, institutions, and social change in the novel. Like Schlesinger, Ellison uses a spatial trope – the depths or underground – to anchor a political intervention. Motivated by the threat of nuclear apocalypse, Ellison uses that trope to critique sociopolitical institutions whose actions betray the underlying egalitarian and collective ideals they proclaim. Ellison applies this critique to Marxian and Black nationalist movements, as well as to mainstream American economic and political institutions, thus crafting a singular reformulation of political radicalism for the postwar era.