Appellee Robert J. Taylor operates a bait business in Maine. Despite a Maine statute prohibiting the importation of live baitfish, he arranged to have 158,000 live golden shiners delivered from outside the State. A federal grand jury in Maine indicted Taylor for violating and conspiring to violate the Lacey Act. Taylor moved to dismiss the indictment on the ground that Maine's import ban unconstitutionally burdens interstate commerce. The District Court found the statute constitutional and denied the motion to dismiss. Taylor then entered a conditional plea of guilty reserving the right to appeal the District Court's ruling on the constitutional question. The Court of Appeals for the First Circuit reversed, agreeing with Taylor that the underlying state statute impermissibly restricts interstate trade. Maine appealed.