Even for a president who has made "fake news" a rallying cry, Donald Trump's Nov. 7, 2018, press conference was a contentious affair. But the bile he directed at his questioners—calling CNN's Jim Acosta a "terrible person" and attacking the media as "the enemy of the people"—was overshadowed when the White House revoked Acosta's press pass the same day, falsely claiming he had "placed his hands" on an intern.

As media organizations absorbed the implications for their businesses and for the nation, Gibson, Dunn & Crutcher's Theodore Boutrous and Theodore Olson were already leaping into action. Before the night was over, they had hashed out a strategy with CNN and assembled a team to counter the White House on First Amendment grounds.

The case was quintessential Gibson Dunn: high-profile, high-impact and high-stakes.

"There was concern that, if you lose, there will be a bad precedent," Boutrous recalls. "Our view was, well, if we don't file a suit, if we're not willing to defend the First Amendment, then who cares?"

The result was quintessential Gibson Dunn, too: a gigantic win, delivered under great pressure, with lasting import for an industry and for the country. Boutrous, Olson and partners Anne Champion and Joshua Lipshutz brought their suit, argued their case, and secured an order restoring Acosta's pass in just nine days. It was no surprise that when the White House this year pulled the credentials of another reporter, Playboy's Brian Karem, Boutrous got the assignment—and won again.

What's the firm's secret? The size of its litigation department doesn't hurt, with more than 200 partners and 500 associates accounting for more than half of the firm's head count and revenue. Gibson Dunn also has its superstars—Olson and Boutrous among them—at both the trial and appellate level, sprinkled across practices, time zones and (increasingly) national borders. And, of course, it wins cases for Fortune 50 clients facing enormous threats.

Partners: 208 Associates: 518 Other: 29. Department as Percentage of Firm: 56.8% Percentage of Firm Revenue: 54.7%

But other firms have hundreds of litigators, marquee advocates and lots of offices. And every firm among our finalists can point to impressive victories with important legal issues and vast sums in the balance. What sets Gibson Dunn apart is how many of its cases check all those boxes: mind-boggling financial stakes, major unsettled legal questions and a nexus to big, national issues—from the First Amendment to antitrust, data privacy, climate change, immigration, and the gig economy.

Take the firm's double-barreled victory over the U.S. Securities and Exchange Commission's in-house enforcement regime, which had long been challenged unsuccessfully on the grounds that the agency's administrative judges were unconstitutionally appointed.

In New York, litigation department co-chair Randy Mastro beat back an administrative action against client Lynn Tilton of hedge fund Patriarch Partners after being tapped to replace another firm just weeks from trial. "No one gave us any odds on winning that case, because the deck is stacked in those proceedings," Mastro says, noting that a challenge to the SEC before one if its own judges was considered nearly unwinnable. But Mastro did win, persuading an SEC judge to fully reject the agency's own $200 million case in September 2017.

An even bigger victory came nine months later in Washington, when partner Mark Perry persuaded a 6-3 U.S. Supreme Court majority to rule against the agency in Lucia v. SEC, a major separation-of-powers decision holding that SEC administrative law judges are "officers of the United States" subject to the Appointments Clause.

The opinion was not only a win for Gibson Dunn's client; it also tilted the balance of power away from the administrative state, with implications beyond the SEC. And it came on the heels of another successful agency challenge, when then-partner Eugene Scalia—now U.S. Secretary of Labor—persuaded the Fifth Circuit to strike down the Labor Department's fiduciary rule, hacking away massive regulatory obligations for the investment industry.

The SEC and Labor Department cases were just two of the key appellate wins that the firm secured. In a blockbuster decision in May 2018, Olson, a former U.S. solicitor general, persuaded the Supreme Court in Murphy v. NCAA to strike down a 1992 federal sports-betting ban, helping to reshape the economics of both professional athletics and online gambling. On the immigration front, Boutrous and partner Ethan Dettmer were part of the coalition that successfully challenged the White House's decision to rescind the Deferred Action for Childhood Arrivals program before the Ninth Circuit, paving the way for Olson to argue for the so-called Dreamers before the Supreme Court in November. (A decision is expected by the summer.)

The firm's trial court record was just as impressive. In the landmark AT&T-Time Warner merger case, Texas partners Robert Walters and Michael Raiff, representing AT&T, were part of the multifirm team that beat back the government's antitrust challenge. In the continuing fight over corporate responsibility for climate change, Boutrous helped persuade judges in New York and California to reject municipalities' theories of liability against Chevron and other oil companies.

Chevron is a longtime Gibson Dunn client, with a relationship cemented by Mastro's knack for fending off multibillion-dollar cases against the company over the years. But the firm has also made inroads with clients in younger industries. Those include Facebook, which is relying on Gibson Dunn in a tangle of privacy and data security cases, and gig economy companies. For Grubhub, partners Michele Maryott and Theane Evangelis scored a trial win in a bellwether employment case after trimming away class action claims, drawing a roadmap for other sharing economy defendants whose workers seek greater employment protections.

Cultivating technology clients was part of a determined strategy by the firm, says partner Debra Wong Yang, a former U.S. attorney in Los Angeles who co-founded Gibson Dunn's information technology and data privacy practice group nearly a decade ago—long before consumers' digital privacy or the classification of gig economy workers were priorities before the courts or on Capitol Hill.

"You could see where things were going," says Yang, whose Silicon Valley clients have included Uber. "So we got ourselves trained up. We got ourselves ready."

The firm's combination of discipline and savvy keeps clients coming back. CNN general counsel David Vigilante, who worked with Boutrous and Olson in the Acosta case, says he trusts Gibson Dunn lawyers to have the intellectual curiosity to come up with good ideas—and the skills to apply them.

"The biggest premium for me, other than are you smart and are you nice, is are you curious," Vigilante says. "Some people just crackle. They seem to attract lawyers like that."