A n unfortunate development over the past 30 years has been the politicization of the regulatory process. Egged on by Congress, the White House or powerful interest groups, too many regulators have pursued ideological agendas that seek to accomplish through rule-making and enforcement actions (or non-actions) what could never have been done through legislation.

Tim Muris, who steps down this week as chairman of the Federal Trade Commission, has avoided those pitfalls. Although he is a "law and economics" conservative who met frequently with friends at the Bush White House, Muris surprised many critics by turning out to be an aggressive regulator willing to step on the toes of a number of powerful industries. He's been so careful to build on the work of his predecessors that, even as his pictures were taken down from the walls yesterday, he was describing his tenure and that of Democratic predecessor Robert Pitofsky as one seamless period marked by bipartisan consensus. And, get this: Pitofsky and many of those who served with him feel the same way.

Muris and Pitofsky were similar chairmen in many ways. Both did two tours on the FTC staff before becoming chairman, a job for which they seemed to have been preparing all their lives. Both are academics who love nothing more than engaging in an intellectual argument with a visitor or presiding over conferences bringing together the best minds in the world to weigh in on big, important issues. Each set out a clear agenda, stuck to it and got it done.

Muris's agenda included a determined and creative consumer protection effort. He targeted abusive lending practices and deceptive credit counselors, and exposed false claims made by peddlers of products alleged to take off pounds and harden abs in just seven days. When the Colonel started marketing Kentucky Fried Chicken as health food, Muris was quick to call him on it. And in terms of touching the lives of Americans, nothing is likely to rival the do-not-call registry that shields about 60 million households from unwanted telemarketing calls.

On antitrust issues, Muris's instinctive distrust of government regulation ironically led him to open up a rich new realm for the FTC, going after state and federal rules used by businesses to reduce competition. His competition bureau went after big drug companies that used patent laws to delay the introduction of generic competition and a big oil company that used a patent on a clean-fuel formula to drive up gas prices in California. His economists issued reports showing how bans on Internet sales needlessly increased the price of wine and contact lenses, and how patents on fairly ordinary ideas and concepts were being used to stifle competition and creativity in high technology. Long-neglected mergers of hospitals and medical practices received heightened scrutiny.

Muris, however, was reluctant to block mergers even in concentrated industries unless someone could show empirical evidence of past or future anti-competitive behavior -- an unreasonably high standard for a law that by its nature requires a degree of speculation. The commission's 3 to 2 approval of the merger of the Princess and Carnival cruise lines was just such a mistake, as confirmed this week when the two remaining industry giants announced a crackdown on travel agents who dared to sell cruises at a discount.

Muris also seems to have a blind spot when it comes to the oil industry, which claims to have realized vast savings from recent mergers and asset sales but has yet to show how even a penny of that has made its way to the pockets of consumers. Muris's defense of high gas prices is that they simply reflect the fluctuating world market price for oil -- an explanation that conveniently ignores that the "market" price is manipulated by the price-fixing OPEC cartel, which counts on the major oil companies as partners, customers and collaborators.

That said, Tim Muris heads back to George Mason University having showed that it is still possible for a smart and determined regulator to ignore special interests, avoid the partisan swamp and actually do some good for the American consumer.

Steven Pearlstein can be reached at pearlsteins@washpost.com.