F.T.C. Chair Faces Criticism in Congressional Hearing

The losses have not weakened her focus on the tech industry. On Thursday, the F.T.C. filed to appeal the court decision on Microsoft’s deal with Activision. Also this week, it opened an investigation into the artificial intelligence start-up OpenAI, which makes the ChatGPT chatbot, for potentially harming consumers with privacy and security lapses and for spreading false information about individuals.

Ms. Khan’s strategy may take years to pay off, said Megan Gray, a lawyer and a former member of the F.T.C.’s staff. “She knows that this is a long-term effort and this not a Pollyanna new antitrust push,” Ms. Gray said.

The White House reiterated its support for Ms. Khan on Thursday. “Chair Khan has delivered results for families, consumers, workers, small businesses and entrepreneurs,” Michael Kikukawa, a White House assistant press secretary, said in a statement.

At the hearing, the court loss this week provided more ammunition for Republicans in their complaints against the F.T.C.

Representative Darrell Issa, Republican of California, criticized Ms. Khan’s judgment in pursuing the case to block Microsoft’s acquisition of Activision. Regulators rarely bring cases against so-called vertical mergers of two companies that don’t directly compete. That was the case with Microsoft, a console maker, and Activision, a video game maker. And Sony, Microsoft’s competitor, has a big market share, Mr. Issa said.

He also criticized the F.T.C. for pursuing a case to block the pharmaceutical giant Illumina from merging with Grail, a cancer test maker, after a judge in the agency’s internal court disagreed with its fight to prevent the deal.

“My problem here today is that you’re a bully,” Mr. Issa said. “The reality is we are a global market, and you are thinking only of who you want to go after for some reason. And I cannot find your logic.”