Last April, dozens of lawyers and their guests gathered at the Columbus Inn in Wilmington, Del. The revered restaurant, with roots tracing back more than two centuries, was once a hangout for Buffalo Bill. Yet on this cloudless night, the crowd would have been happy to be partying almost anywhere.

Hours earlier, the lawyers and their client, Dominion Voting Systems, had negotiated an extraordinary $787 million settlement with Fox News. The deal was struck moments before opening arguments in a hotly anticipated defamation trial, in which Fox was accused of airing inflammatory lies that Dominion had thwarted Donald J. Trump in the 2020 presidential election.

Now the company’s two main law firms could enjoy the spoils.

Susman Godfrey would pocket a thick slice of the settlement that Fox had just wired over.

Clare Locke, a smaller firm that specializes in the niche field of defamation law, wouldn’t get a cut of the settlement. But Dominion had already paid it millions of dollars in fees, and the victory offered the firm the potential for something even greater.

Run by the husband-and-wife team of Tom Clare and Libby Locke, the firm had helped popularize efforts by wealthy and powerful clients to attack news organizations and delegitimize or kill unfavorable articles. Ms. Locke in particular had taken to publicly arguing that much of the news media was unethical, though she also voiced support for free speech.

The triumph against Fox gave the firm’s founders an opportunity to widen their appeal. They could argue that Clare Locke was not an enemy of the free press or the First Amendment, but a champion of truth and a guardian of democracy.

At the Columbus Inn, the exhausted but jubilant lawyers drank and toasted one another late into the evening.

“Celebrating tonight,” Ms. Locke wrote in an email at 10:55 p.m. She added, “It’s a bit crazy here on our end.”

It was even crazier than she realized. The case had made legal history — but it had also torn the firm apart.

Friction among lawyers at Clare Locke had been building for years, and much of it centered on Ms. Locke. Her colleagues chafed at her management style. Some feared that her public embrace of conservative causes, including on Fox News, was alienating clients.

Then came Dominion.

Mr. Clare had been committed to the case since late 2020. Ms. Locke had at times publicly boasted about the Dominion lawsuit, too — but she also repeatedly tried to pull her firm off the case, including shortly before the trial was set to begin, according to several people with knowledge of the firm’s inner workings. Many of the more than two dozen people interviewed for this article requested anonymity to avoid professional repercussions.

While Ms. Locke’s efforts failed, they had shattered morale and confidence inside the small but formidable firm.

As she made her rounds in the dark, crowded room at the Columbus Inn, Mr. Clare and Ms. Locke didn’t know that most of their firm’s partners had already decided to resign.

In a series of letters totaling nearly 60 pages, Mr. Clare and Ms. Locke said The New York Times was spreading falsehoods about them and their firm. They said the firm had not tried to get off the Dominion case: “To the contrary, Tom and Libby were pushing for the firm to have an even larger role.”

The pair accused The Times of relying on sources “with a vested interest in maligning Tom and Libby’s reputation to grow their own fledgling business.” And they said that Clare Locke had faced The Times in court and that the article was “clearly seeking to strengthen the paper’s position in pending and future litigation.”

Keep calm and sue

Before starting their boutique defamation shop, Mr. Clare, 53, and Ms. Locke, 44, worked at the giant international law firm of Kirkland & Ellis, where both were partners.

Mr. Clare, a workhorse who sometimes billed nearly 3,000 hours a year, had been an understudy to a senior partner whose practice included high-profile defamation cases. Ms. Locke arrived at Kirkland in 2006 after graduating from Georgetown University’s law school, where she’d led the local chapter of the conservative Federalist Society. Mr. Clare soon became a mentor.

In 2014, they founded Clare Locke. The public explanation, which they recounted in interviews over the years, was that they had grown frustrated at Kirkland, which sometimes blocked them from taking defamation cases that conflicted with the firm’s bread-and-butter work for corporate clients.

There was more to their origin story, though. Senior partners at Kirkland had fielded complaints that Mr. Clare and Ms. Locke, who at the time were married to other people, were having an affair, according to six current and former Kirkland employees. Ms. Locke often reported to Mr. Clare.

Mr. Clare and Ms. Locke denied at the time that they were romantically involved. But Kirkland partners told them that if the relationship continued, at least one of them would have to leave the firm, four of the current and former employees said.

Mr. Clare and Ms. Locke said that “this is not true and any suggestion to the contrary would be false and defamatory.” (A Kirkland spokeswoman declined to comment.)

Mr. Clare and Ms. Locke set up their firm in the wealthy Washington suburb of Alexandria, Va., near where they both lived with their respective spouses and children. They recruited a small group of lawyers and staff members from Kirkland to join them.

One morning in 2015, the new firm’s lawyers were surprised to receive a mass email from Ms. Locke’s husband, Spencer R. Fisher. He wrote that he had discovered that Ms. Locke’s relationship with Mr. Clare was more than professional. Mr. Clare and Ms. Locke had previously assured employees that they were not romantically involved, according to Megan L. Meier and Andy Phillips, two of Clare Locke’s first recruits. Mr. Fisher’s email planted seeds of distrust, with some employees beginning to worry about their ability to communicate openly with their bosses.

Mr. Clare and Ms. Locke denied telling Ms. Meier and Mr. Phillips that they were not romantically involved, and they said the employees did not mention concerns about a lack of trust.

Mr. Fisher, in an email to The Times, didn’t answer questions about the message he had sent to Clare Locke employees and others. “Libby is not only a brilliant lawyer, but also a compassionate and giving person,” he said. “She has a strong sense of ethics and responsibility, and she is always willing to help those in need.”

Clare Locke’s fortunes soon soared. In 2016, the firm won a roughly $3 million jury verdict on behalf of a dean at the University of Virginia who had been defamed by a deeply flawed article in Rolling Stone magazine. The victory generated national headlines.

A procession of lucrative clients came calling for help combating the media. There were hedge fund kingpins and Silicon Valley executives accused of personal or business misconduct. There were politicians facing allegations of sexual improprieties. There were litigious foreign businessmen. There was a wing of the Sackler family, of OxyContin notoriety. There were Russian oligarchs like Oleg Deripaska, although Clare Locke has since stopped representing him.

“Keep calm and file libel suits,” read a framed sign hanging in Clare Locke’s office.

The firm represented the former Alaska governor Sarah Palin and Project Veritas, the group of right-wing provocateurs, in lawsuits against The Times. The Project Veritas case is ongoing.

Litigation, however, tended to be a last resort. More frequently, Mr. Clare, Ms. Locke and their colleagues sought to derail or shape stories before publication. To do this, they cranked out warning letters to reporters, editors, publishers and their lawyers trying to poke holes in planned articles and accusing journalists of bias, unethical behavior and getting facts wrong. Citing the possibility of litigation, the letters often instructed news organizations to preserve all documents, notes and other materials associated with their reporting.

Mr. Clare and Ms. Locke used similar tactics as The Times prepared this article. In one email to a Times lawyer, Ms. Locke called this reporter “a misogynist and a snake.” She and Mr. Clare told The Times to preserve all documents related to this article.

The pair said they only pursued media outlets that got facts wrong, and they denied trying to kill unfavorable articles. “The firm takes clients who have valid complaints about how they were mistreated by the media,” they said.

“They are fierce advocates for their clients and not for themselves,” said Leland Vittert, a former Fox News correspondent who is now an anchor at the cable network NewsNation. He said he became friends with Mr. Clare and Ms. Locke after they helped his family’s business in Michigan confront negative local media coverage in 2016. “I’ve always seen them as people who just care about the truth.”

Piloting the Cessna

Clare Locke generally charged by the hour; Mr. Clare’s rate sometimes was about $1,800, according to people with knowledge of the firm’s finances. (Mr. Clare and Ms. Locke wouldn’t discuss the firm’s finances but said that they charge the same hourly rate.) The firm often required clients to pay tens of thousands of dollars in upfront retainers — and more if the client wanted to explicitly threaten to sue. Even fairly anodyne letters to media organizations could cost clients nearly six figures.

Before long, Clare Locke was pulling in tens of millions of dollars a year in revenue. While the firm had several partners, Mr. Clare and Ms. Locke were the only two with ownership stakes, and the people familiar with the firm’s finances estimated that the founders each took home millions of dollars a year.

In 2017, after divorcing their spouses and about three years after starting their firm, they married. Ms. Meier, the first recruit to their firm, officiated their Georgetown wedding.

The couple bought a $4.3 million house down the street from their firm’s offices. They purchased a lakefront home in Ms. Locke’s native Georgia and spent long stretches at a property in the Turks and Caicos, according to public records and acquaintances. Mr. Clare piloted the firm’s Cessna jet between those and other locations.

Colleagues described both Mr. Clare and Ms. Locke as smart and hard-working; in their written response to The Times, the couple noted that she twice returned early from maternity leaves “because of her dedication to her work and clients.”

In other ways, though, they differed. He was risk-averse and calm, colleagues said. She was entrepreneurial and could be impetuous. At a conference last fall, Mr. Clare and other media lawyers were onstage discussing the Dominion case when Ms. Locke interrupted from the audience to express her view that the media has too many legal protections, according to panelists, some of whom said they were taken aback by her outburst. “We like to joke that ours is a story of fire and ice,” Mr. Clare said on a podcast last year.

Thanks in part to the high-profile Rolling Stone victory, Ms. Locke became a popular booking for TV shows and at public events to debate media law and the scope of the First Amendment.

At a Federalist Society conference, she argued in favor of unmasking journalists’ confidential sources, which would represent a break from longstanding legal precedents and the laws of many states. At that conference and elsewhere, she called for the overturning of a series of Supreme Court decisions that made it harder for public figures to win libel lawsuits — a stance that has gained support from at least two justices, Clarence Thomas and Neil Gorsuch, and would generally benefit her firm’s clients.

Behind the scenes, Ms. Locke helped Gov. Ron DeSantis of Florida organize an event last year to argue for diluting legal protections for the media, according to emails and other documents that The Times obtained via public records requests.

Ms. Locke also appeared three times on Tucker Carlson’s top-rated Fox News show. He praised her as “one of the most successful lawyers in this small but important field” of defamation law.

In internal Slack messages that the firm provided to The Times, Ms. Locke’s colleagues applauded their boss’s performances on Fox News. Privately, though, some worried about what clients would think of the firm’s associating with a show that often trafficked in xenophobia and falsehoods.

About three weeks after the 2020 election, Mr. Clare was preparing for Thanksgiving when he got a phone call from a representative of Dominion.

Conspiracy theorists were flooding the airwaves and social media with false accusations that Dominion’s voting technology, in use in 28 states, was partly to blame for Mr. Trump’s defeat. Trump allies like Sidney Powell, Rudy Giuliani and Mike Lindell were claiming that the company had changed or canceled people’s votes and that it was controlled by the Venezuelan government, among other baseless charges. Outlets like Fox News and One America News amplified the falsehoods.

Dominion’s business was under siege. Its employees faced threats.

Mr. Clare agreed to take the company on as a client. “We recognized right away just how momentous an issue this was, not only for Dominion, but for the entire country and the integrity of elections,” he later told Reuters.

Mr. Clare and his colleagues began sending scores of cease-and-desist letters warning Trump allies, media personalities and news organizations that they were disseminating defamatory lies. The goal was twofold: to stop the smears of Dominion and, failing that, to create a paper trail showing that the potential defendants had been put on notice.

The lies continued.

In January 2021, shortly after a Trump-inspired mob attacked the Capitol, Dominion brought on Susman Godfrey, a litigation powerhouse with more than 150 lawyers. It had become clear that Dominion would file a slew of lawsuits and that Clare Locke was too small to handle them all on its own. In addition, Clare Locke was charging Dominion by the hour, and the bills were already piling up. Susman Godfrey agreed to take the case on contingency, meaning it would get a cut of any settlement or damages but wouldn’t charge the company in the meantime. (Susman Godfrey represents The Times in a copyright lawsuit against OpenAI and Microsoft.)

The complaint against Fox was filed in March 2021, in state court in Delaware, where Dominion and Fox were both incorporated. Including exhibits, it ran to 441 pages. It accused Fox of knowingly providing a platform for guests to lie about Dominion, and it accused numerous hosts, including Mr. Carlson, Maria Bartiromo and Lou Dobbs, of endorsing and repeating those lies. The suit sought more than $1.6 billion in damages.

Susman Godfrey took the lead on the lawsuit, but Clare Locke had some crucial assignments. It was largely responsible for fending off Fox’s motions to dismiss the case. Mr. Clare and his colleague Ms. Meier also handled depositions of some important Fox figures. One was Mr. Carlson, who emerged from his August 2022 deposition rattled by Mr. Clare. “It was so unhealthy,” he fumed in a leaked video, “the hate that I felt for that guy.”

The biggest bombshells emerged from the discovery process, in which Dominion’s lawyers got to sift through Fox employees’ emails, text messages and other records.

They learned that Fox News had an internal research operation, known as the “Brainroom,” that had concluded that the allegations about Dominion switching votes were “100% false.” Hosts, producers and executives had repeatedly written to one another that they knew the network was broadcasting false claims. “Sidney Powell is lying,” Mr. Carlson had written to his producer in November 2020, even as Fox kept putting her on air.

This kind of documentation was like manna for the Dominion team. Lawyers zapped messages back and forth marveling at what they were reading. “I’m not sure I’ll ever see that type of evidence again,” Mr. Clare said on a panel last year.

Talk of quitting

Despite the apparent strength of Dominion’s case, Ms. Locke was unhappy.

On multiple occasions in late 2022 and early 2023, Mr. Clare told colleagues that he had discussed the case with his wife and that she wanted the firm to stop working on it, according to several people with knowledge of the conversation, including Daniel P. Watkins, one of the Clare Locke partners on the Dominion suit. Mr. Clare told colleagues that he was inclined to grant Ms. Locke’s wish.

“She didn’t want us to work on the case and was very expressive about it,” said Mr. Watkins, who later left to start a new firm.

Mr. Clare denied making the remarks about quitting. “The firm did not want to get off the case, and it did not,” he and Ms. Locke said in their written response. The two said they pushed for a larger role on the case but declined to provide details.

Ms. Locke told people that Clare Locke wasn’t being adequately paid for its extensive work. One issue was that the fee arrangement the firm had negotiated with Dominion imposed a cap on the total amount that could be billed, a limit that was fast approaching. At one point, Ms. Locke said the firm would need to stop working as soon as that cap was hit, even if it happened in the middle of the trial, according to people familiar with the internal deliberations.

Some lawyers involved in the Dominion litigation doubted that was the full explanation. They believed that Ms. Locke wanted to ditch Dominion in part because her law firm and husband were in secondary roles and she had barely any direct involvement in the high-profile case. Mr. Watkins noted that Ms. Locke at times would change the subject when he and his colleagues began excitedly discussing what they regarded as the case of the century.

“She was upset when things didn’t revolve around her,” Mr. Watkins said.

Mr. Clare and Ms. Locke dismissed that as “demonstrably false and absolutely ridiculous, not to mention completely sexist.” While Ms. Locke was not listed in court filings as a lawyer on the Dominion case, they said she made “many contributions,” including helping prepare for and sitting in on the deposition of Mr. Carlson.

Mr. Clare’s colleagues told him repeatedly that quitting the case would be a public embarrassment because people would assume that Dominion had fired the firm, according to lawyers with knowledge of the discussions.

Ultimately, Mr. Clare agreed to stay on the case.

The trial was scheduled for mid-April. Lawyers descended on Wilmington weeks in advance. The Dominion team booked entire floors of the DoubleTree hotel next to the court complex.

Mr. Clare was one of the few Dominion lawyers not staying in Wilmington; to the irritation of some Clare Locke and Susman Godfrey lawyers, he spent most of the first two weeks of April in the Turks and Caicos. He arrived in Wilmington the day before the trial was initially scheduled to begin.

Mr. Clare and Ms. Locke said he was fully engaged in trial preparation while working remotely. He wasn’t scheduled to cross-examine witnesses until later in the trial.

The judge urged the two sides to take a final stab at settling. Negotiations went down to the wire. Finally, just as opening arguments were about to start, there was a deal: Fox would pay Dominion $787.5 million.

The judge announced the settlement to a stunned courtroom. Before the lawyers headed to the Columbus Inn, Fox wired the money to Dominion’s accounts. (In a statement for this article, Dominion said that it was grateful to all of its lawyers “for their world-class support.”)

It was one of the largest defamation settlements in U.S. history, but it seemed to undercut an argument Ms. Locke had been making about constitutional protections of the media.

For years, she had been calling for the Supreme Court to overturn its famous 1964 ruling in New York Times v. Sullivan, which required public officials to overcome high hurdles to win defamation cases. Ms. Locke and her allies argue that Sullivan, as well as a handful of subsequent decisions, makes it all but impossible to hold the media accountable when they wrecked reputations.

But the Sullivan precedent didn’t get in the way of Fox’s being held to account to the tune of nearly $800 million.

Ms. Locke, however, did not back down. To her, the Dominion lawsuit revealed a fundamentally dishonest media that had been emboldened by undeserved constitutional protections. “I think the settlement shows just how comfortable the mainstream press has become under the Sullivan regime lying to the American public,” she said the week after the deal.

Anger and an exodus

Even though Clare Locke had stuck with Dominion, questions about its commitment to the case had sapped some partners’ confidence in the firm’s leadership — the latest in a long list of grievances.

Some partners felt that because they didn’t have equity stakes in the firm, they were being underpaid. They were unhappy when the firm hired a lawyer from Project Veritas, an organization whose tradecraft included deceptive tactics, without consulting the partners. They resented what they saw as Ms. Locke’s harsh treatment of some subordinates. And they worried that prospective clients would be turned off by the perception of Ms. Locke as an ideological warrior.

By the time of the Dominion settlement, four Clare Locke partners — Ms. Meier, Mr. Watkins, Mr. Phillips and Dustin Pusch — had decided to quit to start their own law firm.

Mr. Clare and Ms. Locke said that the four “never expressed ‘frustrations’ or ‘resentment’ to Tom or Libby” and had said in self-evaluation memos that they had confidence in the firm and its management. They said that the partners had each earned millions of dollars and that some of them had praised the firm’s compensation policies.

One morning in early August, the four partners gathered in a conference room in Clare Locke’s offices, according to Mr. Watkins and other people familiar with the meeting. The firm’s two founders joined via Zoom.

Ms. Meier and her colleagues broke the news: They were going to issue a news release announcing the creation of their new firm, which would be called Meier Watkins Phillips Pusch. Aside from Mr. Clare and Ms. Locke, there would be only one remaining partner at their firm.

The two founders seemed stunned. Mr. Clare, whose camera was off for most of the meeting, said he wasn’t sure that the firm would be able to continue to operate. (Mr. Clare and Ms. Locke said that “there was NEVER a moment when anyone thought or said that the firm would not survive.”)

Ms. Locke asked when the departures were effective. “Twenty minutes ago,” Mr. Watkins responded.

There was silence. Ms. Locke began to cry.

Headline-worthy clients

Any concerns about Clare Locke’s ability to keep operating quickly proved unfounded. The firm replenished its ranks by promoting associates to partners and hiring new lawyers, including another veteran of Project Veritas.

“Clare Locke is a better and stronger law firm today than before the departures,” Mr. Clare and Ms. Locke said. They said the former partners’ “true motivation” for creating their own firm was to snatch for themselves a multimillion-dollar fee from an ongoing defamation lawsuit, which Mr. Watkins and others had filed on behalf of a company called Kytch while at Clare Locke.

Mr. Phillips disputed that. He said that Kytch fired Clare Locke last fall, after the four partners had created their new firm, which is now representing the company. (Clare Locke this month filed a lawsuit seeking legal fees from Kytch.)

At the same time, Clare Locke kept attracting headline-worthy clients.

Last fall, Harvard’s president, Claudine Gay, came under fire from activists and alumni like the hedge fund manager Bill Ackman, who accused her of plagiarism. The university hired Clare Locke to defend Ms. Gay and to warn The New York Post about the prospect of litigation if it published articles about the allegations. The Post ran its stories, and Ms. Gay soon resigned as president.

Then Clare Locke began representing Mr. Ackman. In January, Business Insider published articles accusing his wife, Neri Oxman, of plagiarism. Mr. Ackman hired Clare Locke to write a 77-page letter threatening the outlet with litigation if it didn’t retract the claims. Business Insider has stood by its articles.

In a recent interview with The Times, Mr. Ackman said he was upset with the media’s power “to destroy lives.” Announcing the letter on X, he called Ms. Locke and Mr. Clare “the rock stars of defamation law. They should be your first call if something like what happened to Neri and me happens to you.”

Their firm, Mr. Ackman noted, was “best known for its recent representation of Dominion.”

Kitty Bennett contributed research.