“As societies grow decadent, the language grows decadent, too,” Gore Vidal wrote in 1986. “Words are used to disguise, not to illuminate, action: you liberate a city by destroying it.” In recent days, the Court’s conservatives have issued one ambitious opinion after another. They expanded President Trump’s powers to fire independent regulators, rescind deportation protections, and turn away asylum seekers; weakened state authority to enact gun control; narrowed the ability of religious minorities to vindicate their free-exercise rights; eroded the due-process rights of green-card holders; and handed big wins to multinational oil and tech companies. Yet anyone not paying close attention would likely miss the Court’s radicalism. The justices’ language in most cases obscured their opinions’ effects; the word decadent fits. Using invocations of precedent to disguise rather than illuminate, the conservative justices pretend to preserve what they are overturning. This duality—sweeping remaking of law presented as continuity—has become a hallmark of the Roberts Court. Precedent matters. The idea is so axiomatic to the legal system that stating this risks condescension. But the basics are …