[6] At Foley, Hoag, Lynch was part of the team that represented W.R. Grace in the connection with a groundwater contamination lawsuit later profiled in the work A Civil Action.
Clinton renominated Lynch on January 11, 1995, to fill the seat vacated by Judge Stephen Breyer, who was elevated to the Supreme Court of the United States on August 3, 1994.
[3] In 1996, Lynch issued a noted dissent from the denial of rehearing en banc in a case in which an all-male First Circuit panel held that a rape committed at gunpoint by a carjacker did not constitute "serious bodily injury" for purposes of a federal sentencing enhancement.
[4] In Natsios v. National Foreign Trade Council (1998), Lynch wrote an opinion striking down Massachusetts's "Burma law"—an act, enacted two years earlier, that barred state agencies from contracting with companies that do business in Burma (Myanmar), due to that nation's poor human rights record.
Lynch found that the state law unconstitutionally intruded into the federal government's power to conduct foreign policy.
[13] In Massachusetts v. United States Department of Health and Human Services (2012), Lynch joined a unanimous panel in holding (in an opinion written by Judge Michael Boudin) that the Defense of Marriage Act (DOMA) was an unconstitutional violation of the equal protection principles of the Fifth Amendment, because it denied to same-sex couples the federal benefits enjoyed by opposite-sex couples.
[14] On October 19, 2021, Lynch wrote the majority opinion that upheld Maine's vaccine mandate for health care workers.