In the case of Cooper Industries, Inc. v. Leatherman Tool Group, Inc., 2000, the Supreme Court ruled on a dispute regarding punitive damages and their review by appellate courts. Leatherman Tool Group had sued Cooper Industries for producing counterfeit versions of its products and won in district court with $4.5 million awarded in compensatory damages and $4.5 million in punitive damages due to false advertising claims under the Lanham Act (a trademark infringement statute). On appeal, these amounts were increased to $50 million but this was challenged by Cooper Industries as excessive under the Due Process Clause of Fourteenth Amendment. The Supreme Court held that courts of appeals should apply a de novo standard when reviewing district court determinations of constitutionality for awards involving punitive damages rather than an abuse-of-discretion standard which is more deferential towards lower court decisions; meaning they must independently determine whether or not such awards are constitutional without relying solely on lower courts' conclusions. This decision clarified how federal appellate courts should approach reviews concerning punitive damage awards - ensuring consistency across cases while also protecting defendants from potentially excessive punishments that could violate their rights to due process.

In the dissenting opinion for Cooper Industries, Inc. v. Leatherman Tool Group, Inc., Justice Stevens argued that appellate courts should not review punitive damages de novo (from the beginning), but rather with an abuse-of-discretion standard. He believed that juries and trial judges have a better perspective to make decisions on punitive damages because they are more familiar with the evidence and facts of each case. Furthermore, he contended that this decision contradicts previous rulings where it was established that deference should be given to lower court's findings unless there is clear error or abuse of discretion. The majority’s ruling in favor of de novo review undermines this principle by allowing appellate courts to substitute their judgment for those who were present at trial proceedings.