A progressive, young lawyer and former Supreme Court clerk known for his appellate advocacy and for being one of the leading lights in the legal campaign against the Trump administration has taken a full-time role at Kaplan Hecker & Fink.

Joshua Matz split his time until last month between the Kaplan firm and Gupta Wessler, another prominent progressive law firm known for representing consumers in appellate litigation. He praised his former colleagues but said Kaplan Hecker, where he is counsel, is a bigger firm with the resources to both cater to businesses and to take on cases with major social impact.

“I reached the point where it made sense for me to have a home base,” Matz said.

Matz, who clerked for Supreme Court Justice Anthony Kennedy and the Ninth Circuit's “liberal lion” Stephen Reinhardt, said he anticipated his practice would grow from being focused on the U.S. Supreme Court and other federal appellate courts to include trial-level proceedings and other courts where important legal fights are fought.

He said he appreciated that Kaplan Hecker didn't just take on pro bono mainstays like tenant defense, prisoner suits and challenges to removal orders, but also litigates cases that could have a “massive impact.” Those include challenges to President Donald Trump's official actions and his businesses, and a suit filed by Charlottesville, Virginia, residents who sued a host of racist groups and people allegedly responsible for the protests and acts of violence that shook the city in 2017.

“The firm has this unbelievable model of major high-stakes work” with a social or political angle, but also has “incredibly cool cutting-edge commercial clients” who are “trying to navigate a shifting regulatory landscape,” Matz said. His online biography lists Airbnb and Petal Card Inc. among his clients.

Matz, 34, has some history with Roberta Kaplan, the former Paul, Weiss, Rifkind, Wharton & Garrison lawyer who started her own firm, initially called Kaplan & Co. LLP, in 2017. He joined the firm later that year in what he described as an of-counsel capacity that was less of a full-time commitment than his new role; legal blogger-turned-recruiter David Lat wrote that he was “one of the leading legal minds of his generation” who had a “Rain Man-esque” ability to recall the holdings of obscure Supreme Court decisions.

In his new role, Matz will keep publishing “Take Care,” a legal blog that analyzes and critiques Trump and his administration, and will keep teaching a course titled “Constitutional Litigation and the Current Administration” alongside Amir Ali at the Georgetown University Law Center. He said he anticipates splitting his time between D.C., where he and his husband have a home, and New York, where his new firm's offices are.

Many law firms have an “extraordinarily cautious, almost bunker mentality about doing anything outside the confines of a case,” Matz said. At Kaplan Hecker, he said, that isn't the case; lawyers there can speak and write essays, blog posts and books (Matz has co-authored two with Harvard professor Laurence Tribe) that touch on the cases and causes they devote themselves to, he said.

Recently, Kaplan—who represented Edith Windsor in her landmark case against the United States that found the Defense of Marriage Act's definition of marriage as between a man and a woman to be unconstitutional—has even registered as a lobbyist in New York state to push for legislation on behalf of Time's Up, an anti-sexual harassment movement she has backed.

Kaplan said her efforts in Albany were focused on extending the five-year statute of limitations for second- and third-degree rape, a proposal that Gov. Andrew Cuomo has supported. She said Matz's broad remit dovetails with her firm's efforts to “reinvigorate the sense of lawyers as public citizens” who act through more than their cases.

No one at Gupta Wessler immediately responded to a comment request Monday.