Since becoming chair of the Federal Trade Commission three years ago, Lina Khan has sought doggedly to politicize antitrust law. For decades, regulators and judges have adhered to the consumer-welfare standard, under which antitrust ensures merely that firms pursue low prices, high product quality, and innovation. Khan, by contrast, sees antitrust as a vehicle for “shap[ing] the distribution of power and opportunity across our economy.”

Generally, Khan’s strength has not matched her ambition. In its long-awaited lawsuit against Amazon, for instance, the FTC avoided the sort of pathbreaking arguments that Khan offered in her noted law review article against the company. To have any prospect of success in court, the commission had to contend that Amazon is liable under established antitrust principles.

Recently, though, Khan’s FTC did something quite different. The commission released an order claiming the power to create antitrust rules under its enabling statute, the Federal Trade Commission Act of 1914. This is not another effort to bend or stretch antitrust law as it exists; it’s a bid to rebuild it from the ground up. This is Khan’s most aggressive—and dangerous—move as chair.

Section 5 of the FTC Act directs the commission to prevent businesses from using “unfair methods of competition.” This basically grants it authority to enforce the nation’s antitrust laws—primarily the Sherman Antitrust Act of 1890. Section 5 explains in detail how such enforcement should work. To prosecute anticompetitive behavior, the commission must issue a complaint, hold a hearing, make findings of fact, and then issue a cease-and-desist order.