This article analyzes how the Supreme Court of India, through its activism and assertiveness, has emerged as arguably the most powerful court among democratic polities. Over the past four and a half decades, the Court dramatically expanded its role in the realm of rights and governance, asserting the power to invalidate constitutional amendments under the basic structure doctrine, control judicial appointments, and govern in the areas of environmental policy, monitoring and investigating government corruption, and promoting electoral transparency and accountability. In this article, I argue that the Court’s shift toward greater, yet selective, assertiveness in India’s governance can most adequately be explained by a new theoretical approach—elite institutionalism. This theory posits that the unique institutional and intellectual atmosphere of the Court shaped the institutional perspectives and policy worldviews that drove activism and selective assertiveness in governance. Elite institutionalism expands the scope of regime politics and institutional theories by situating judicial decision-making within the larger intellectual context of Indian judging. The identities of justices on the Indian Supreme Court are a subset of their overall intellectual identity and worldviews, which they share with professional and intellectual elites in India. This article illustrates how “elite meta-regimes” of opinion—the collective values and currents of professional and intellectual elite opinion on sets of constitutional or political issues—shaped justices’ worldviews. The broader shifts in the Court’s activism and assertiveness reflected a shift from the meta-regime of “social justice” to one of “liberal reform.”