An influential federal appellate judge last week expressed great concern about the growing power of tech platforms, including Google and Facebook, and said that anti-monopoly enforcers and courts may have been “too hasty” in abandoning two key traditional tools of antitrust law – the essential facilities doctrine and predatory pricing law.

“When it comes to exclusionary practices” by monopolists, “we may have thrown the baby out with the bathwater,” Chief Judge Diane Wood of the U.S. Court of Appeals for the Seventh Circuit said in a speech at Loyola University on Friday.

Wood, who was appointed to the court by President Clinton, is a widely respected scholar of antitrust law.  Wood also served in the Antitrust Division of the Justice Department, in the 1990s.

The essential facilities doctrine is designed to prevent a monopolist from abusing its control over a service or product so important that competitors need access to it in order to compete. It dates back to a 1912 Supreme Court decision, United States v. Terminal Railroad Association, which ordered the railroads that controlled the only bridges over the Mississippi River in St. Louis to grant access to their rivals on non-discriminatory terms.

The essential facilities doctrine could have a huge effect if applied to platform monopolists like Google or Amazon, which control access to many online markets today. But the doctrine has effectively become a dead letter. The Supreme Court, in the 2004 decision Verizon v. Trinko, criticized the economic rationale of refusal to deal claims (including essential facility claims) and undercut their viability in court. The opinion was authored by Justice Antonin Scalia and joined by Justices Stephen Breyer and Ruth Bader Ginsburg.

Wood last week sharply criticized the Trinko decision for saying “bottleneck monopolies are dead” at “exactly the wrong moment to say that.” At the time of the decision, she said, “We hadn’t yet seen the growth of Google-Alphabet and Facebook and all these other giant things …. We may not have fully appreciated what the competitive challenges of these large, internet-based companies were.”

Predatory pricing law, meanwhile, aims to prevent companies from pricing a product or service below its average cost of production in order to drive existing competitors from the market and deter the entry of new companies. Four Supreme Court decisions since 1986 have made it very difficult to successfully sue large corporations for predatory pricing on the assumption that it was, in the words of the Court, “rarely tried, and even more rarely successful.”

In her speech, however, Wood said that reasoning was mistaken. “There are times that it does happen, times where it really inflicts serious negative consequences on people in the market,” she said.

Wood’s speech was the most important statement in many years on anti-monopoly law and policy by a sitting judge. It marks an important advance in the debate on how to adapt existing antitrust tools to contemporary conditions and suggests some judges may be open to revising existing antitrust doctrines.

Wood’s speech was also important because of the larger concern she expressed about the political consequences of monopolization, or as she put it, concentrating “money and political power in a small number of hands.” America, Wood said, has become “a ‘one dollar, one vote’ system now as opposed to a ‘one person, one vote’ system.”

Wood concluded by saying, “Our forebears were right to recognize” that the distribution of power “is essential not just in economic markets but for political stability.”

“We should get back to work to find ways to implement that insight.”