This is the moment of the conservative crack-up I’ve been waiting for. It’s going to sound small, but it’s the wedge of a wider fissure.

A legal nonprofit just filed a lawsuit against Donald Trump’s declaration of tariffs on China, claiming that the emergency authority he’s invoked gives him no such authority to impose these tariffs. Underneath or alongside that claim is a much deeper argument that it’s time for Congress to claw back its delegation of tariff authority, which it has effectively handed over to the president for decades now.

But here’s what is politically significant about this lawsuit: the nonprofit filing the suit is funded in part by Leonard Leo, the longtime leader of the Federalist Society. By most people’s estimations, Leo was the single most important architect behind all three of Trump’s appointments to the Supreme Court and the overwhelming number of judges Trump appointed to the federal bench during his first term. Leo is the heart and soul of the conservative legal movement, the Principia of the judicial right. His nonprofit, named the New Civil Liberties Alliance (of course), was also the force behind the court’s overturning of the Chevron doctrine last year.