A Congressional Progressive Caucus meeting on Tuesday broke out into a furious argument over the House’s package of antitrust legislation, pitting Rep. Zoe Lofgren, D-Calif., whose district encompasses a large part of Silicon Valley, against the authors of the series of six bills moving through the chamber.

The argument began when Lofgren, one of the most senior Democrats on the House Judiciary Committee and an opponent of the legislation, noted that she had raised an extraordinary amount of money from Silicon Valley companies over the years, but because she ran in a safe blue district, she hadn’t spent any of it on her own campaign since 1996 and instead distributed it widely to other campaigns.

Raising corporate money and spreading it around the caucus is a common tactic deployed by members looking to grow their power. But it is highly unusual to talk openly about the practice on a legislative caucus call. “It’s a pretty shocking thing to say,” one Democrat on the call said.

The debate devolved into unusually personal terms, sources present for the members-only call said. Lofgren argued that the legislation wasn’t just wrongheaded, but also poorly written — considered a cardinal dig on Capitol Hill. Lofgren said that she hadn’t had enough time to review the legislation sufficiently and knocked the unnecessary dead-of-night committee votes, arguing that the approaches the bills take won’t accomplish what could be worthy goals, while doing collateral damage to the economy. Rep. Pramila Jayapal, D-Wash., the chair of the CPC, eventually cut Lofgren off, and noted that despite representing Seattle, the home of Amazon, she has been willing to take on Big Tech.

Antitrust Subcommittee Chair David Cicilline of Rhode Island, the lead author of much of the legislation, was blunt in his response to Lofgren. “Cicilline lost it,” said one Democrat on the call and, according to multiple sources, he accused Lofgren of merely parroting “industry talking points.”

“You may disagree with the bills, you may have other interests you’re trying to protect, but to suggest members of the subcommittee of the Judiciary Committee don’t understand them, with all due respect, is deeply offensive,” Cicilline said, according to multiple sources.

Late last month, the Judiciary subcommittee that handles antitrust policy passed six bills in a marathon 29-hour session. They’re aimed at reining in and breaking up Big Tech, and Lofgren emerged as the bills’ most outspoken Democratic opponent.

That the arguments made by Lofgren against the legislation are the same as those made by Big Tech is not in dispute. But to question the motivation of those arguments, or the link between those positions and campaign funds, is considered wildly out of bounds on Capitol Hill — something that is not to be spoken out loud. One member said Lofgren was offended enough that she was considering organizing a letter of complaint from the California delegation to House Speaker Nancy Pelosi.

Rep. Jerry Nadler of New York, the Judiciary Committee chair, also spoke up against Lofgren, though sources differ on how aggressive his rhetoric was: Some said he joined in the ad hominem attacks, while others said he merely stood up for the committee process and for the legislation, though he seemed to enjoy seeing his longtime rival shredded by other committee members.

Nadler and Lofgren have a contentious history. In 2017, when Judiciary Committee Chair John Conyers of Michigan stepped down from Congress, Nadler was in line to succeed him, but Lofgren challenged Nadler in what The Intercept described at the time as “the first battle of the anti-monopoly era.”

The article quoted antitrust attorney Jonathan Kanter as saying, “It certainly may raise questions to have someone from Silicon Valley in a position where one of the key responsibilities is to oversee the conduct of Silicon Valley.” Partly if not primarily as a result of those dynamics, Nadler beat her for the gavel, and the committee has been in aggressive pursuit of bipartisan antitrust legislation since. The committee embarked on a two-year investigation of Big Tech, primarily overseen by Judiciary staffer Lina Khan. Lofgren objected to the product of that investigation, a report which recommended legislation to tackle Big Tech’s runaway power.

That staffer, Khan, is now chair of the Federal Trade Commission. And that antitrust attorney, Jonathan Kanter, is rumored to be the leading choice to run the antitrust division at the Department of Justice.