Courts are the last defence against tyranny

India and the United States are the world’s two biggest democracies, and both of them seem to be in danger. In each of them populist federal governments are deliberately polarising the population, radicalising the politics, and seeking to undermine the impartial rule of law. In other places, such an approach has often ended in tyranny or civil war.

India’s Prime Minister Narendra Modi is a classic populist leader, although he prefers an austere and religious style to the more florid approach...