He is interested in how law operates through everyday life, particularly what people-both experts and ordinary men and women-think the law is and how they use this knowledge to negotiate their daily lives. Professor De's book A People's Constitution: The Everyday Life of Law in the Indian Republic (2018) explores how the Indian constitution, despite its elite authorship and alien antecedents, came alive in the popular imagination such that ordinary people attributed meaning to its existence, had recourse to it, and argued with it. Mapping the use and appropriation of constitutional language and procedure by diverse groups such as butchers and sex workers, street vendors and petty businessmen, journalists and women social workers, it offers a constitutional history from below. His current research, "Rights from the Left; Decolonization, Diasporas and the Global History of Rebellious Lawyering," offers an alternate history of universal rights and civil liberties that arose out of Asia and Africa during the period of decolonization. The project follows the careers of lawyers who defended unpopular causes across space and time, to offer an alternate history of universal rights and civil liberties that arise out of Asia and Africa and is mediated through Indian, Chinese and Caribbean diasporas.