The Microsoft investigation and trial, which I covered, was fairly narrowly focused. It was about market dominance and the software giant’s tactics to stifle innovation.

The second half of the 1990s, when the Justice Department and a group of states investigated and then filed a major antitrust suit against Microsoft, were banner years economically. It was not only a period of strong overall growth but a time when productivity rose. For a few years, income gaps narrowed.

Microsoft was a purely economic case. “But now we’re seeing an evolution in antitrust, to take in greater social and political concerns, as well as economics,” said Maurice Stucke, a former Justice Department antitrust official and a professor at the University of Tennessee College of Law. “Antitrust is starting to capture the public imagination in a way that Microsoft never did.”

Current antitrust thinking is expanding to take in matters like the control of data and privacy. Since the 1980s, a central focus of antitrust has been a dominant company’s power to increase prices. But there is a lively debate now about so-called nonprice components of competition. A loss of privacy to a data-harvesting giant like Facebook or Google, for example, can be cast as reducing the quality of the service and thus as a signal of monopoly power.

“Nothing’s free,” Makan Delrahim, head of the Justice Department’s antitrust division, said at the Times’s DealBook conference last month. “If consumers think they’re getting any service for free, they’re being misled.”

Data, Mr. Delrahim explained, is an asset for internet companies, and gathering and analyzing large amounts of personal data is not necessarily a problem. But digital data, he added, “can give you market power. And its abuse would be a violation of antitrust law.”

In the last couple of weeks, Representative Doug Collins, Republican of Georgia, who is the ranking minority member of the House Judiciary Committee, has been a fixture on cable TV news as a hyperventilating, partisan opponent of impeachment. But in an interview last month for an article on a Judiciary subcommittee’s antitrust investigation of the big tech companies, Mr. Collins was a voice of bipartisan reason.