A former clerk for the U.S. Supreme Court, D.C. District, and Northern District of Illinois, Greg Dubinsky
has a wide-ranging practice in which prominent clients call upon him to handle high-profile, complex matters across the country requiring the highest level of legal acumen and trial know-how.
Greg is currently involved in two of the nation’s most closely watched antitrust disputes. In one, Greg acts as lead counsel to the plaintiffs in a major antitrust class action against a Wisconsin-based hospital network alleging that it has used its monopoly power in the region to overcharge for medical services. Greg is also a senior member of the HSG team acting as national lead trial counsel for Visa in the defense of multidistrict antitrust class actions and opt-out litigation asserted by the world’s largest retailers, challenging network rules that benefit all domestic cardholders. After HSG helped Visa reach a historic $5.6 billion settlement with 12 million merchants, Greg’s team is now preparing for an April 2026 trial with Target, Macy’s, and other retailers that is one of the most anticipated civil trials of the upcoming year.
In matters with implications for free speech, Greg served as the lead lawyer for the online video platform Rumble, scoring dismissals of two putative class actions alleging Rumble violated the Video Privacy Protection Act by disclosing to Facebook its subscribers’ personal information. Following those wins, he again obtained the complete dismissal of a putative class action under the VPPA, this time for IBM.
Former New York Governor Andrew Cuomo looked to Greg to challenge action by the state Commission on Ethics and Lobbying in Government, which had charged the former governor with ethics violations related to a deal for a book about his efforts in the Covid-19 pandemic. Greg crafted a constitutional separation-of-powers argument that won at New York’s trial court and intermediate appellate court. New York’s highest court issued an adverse split decision on the issue in January, after Greg argued the weighty issue regarding the relationship between the executive and legislative branches of New York’s government.
In another high-profile matter that attracted media attention, Greg scored total victories for the National Basketball Association at the district court and the U.S. Court of Appeals for the Sixth Circuit in a lawsuit by an aspiring agent accusing the league of antitrust violations. The court agreed with Greg’s position that the NBA’s only relevant activity in the case—collectively bargaining with its union—is exempt from antitrust law. Greg followed up with another win for the NBA in the U.S. District Court for the Western District of Tennessee in a case raising RICO and trademark infringement issues.
Greg also played a major role on an HSG team that tried a $700 million antitrust case against Rupert Murdoch’s News Corp. He oversaw the damages component of the case, in which HSG represented a company controlled by the legendary investor Ron Perelman that competed in the valuable market for “in-store promotions.” HSG’s client, Valassis Communications, claimed that News Corp. had unlawfully maintained a monopoly. Greg played a pivotal role in defeating News Corp.’s motion for summary judgment. As part of overseeing the damages component, Greg deposed News Corp.’s damages expert. After a three-week jury trial, the case settled for nine figures during jury deliberations.
Greg co-authored an amicus brief on behalf of a bipartisan group of state legislators that Supreme Court Justice Elena Kagan quoted in her concurring opinion in Gill v. Whitford, the challenge to partisan gerrymandering in Wisconsin. He also submitted an amicus brief to the Supreme Court on behalf of a bipartisan group of 10 U.S. senators in support of American victims of terrorist attacks concerning the proper interpretation of the Antiterrorism Act. SCOTUSblog invoked Greg and his team’s amicus brief on behalf of the Brennan Center for Justice in Benisek v. Lamone as an example of a “top” amicus brief. And in a major partisan gerrymandering case in New York, a justice of the Appellate Division invoked an amicus brief Greg co-authored for the League of Women Voters of New York State; the New York Court of Appeals agreed with that analysis in ruling that the legislature’s process for enacting redistricting maps violated the state constitution.
Greg also maintains a significant pro bono practice. In one matter, he assisted an Afghan national who had trained with U.S. forces (and faced threats by the Taliban) in asylum negotiations with the government. At the Ninth Circuit, he secured the reversal of a lower court’s dismissal of claims brought by a transgender victim of prison sexual assault who faced retaliation, and he obtained the first successful bail motion for an immigrant detainee in the Second Circuit.
Greg has been named to the Lawdragon 500 X – The Next Generation list since 2023 and to Benchmark Litigation’s 40 & Under List since 2022, and has been recognized as a Rising Star by the New York Law Journal (2021) and by Super Lawyers since 2020.
