356 U.S. 86 (1958), argued 2 May and 28–29 Oct. 1957, decided 31 Mar. 1958 by vote of 5 to 4; Warren, joined by black, Douglas, and Whittaker, for the plurality, Brennan concurring, Frankfurter, Burton, Clark, and Harlan in dissent. This case was decided on the same day as Perez v. Brownell, in which a majority of 5 to 4 affirmed Congress's power to take away the American citizenship of a person who had voted in a foreign election. With Justice William Brennan, who had been in the majority in the Perez case, changing sides, the Court in Trop held that Congress had no power to withdraw an individual's citizenship for wartime desertion from the military. Chief Justice Earl Warren, who had dissented in Perez on the ground that Congress was entirely without power to denationalize anyone without consent, wrote for the plurality in Trop, which consisted of the four Perez dissenters. Warren reiterated the broad constitutional argument he made in Perez and further contended that Congress could not impose expatriation as punishment without violating the Cruel and Unusual Punishments Clause of the Eighth Amendment. Involuntary expatriation, wrote Warren, was cruel and unusual punishment because it constituted “the total destruction of the individual's status in organized society” (p. 101). Brennan, concurring separately, merely concluded that expatriation for wartime desertion was not a rational exercise of the war power. The Eighth Amendment argument, therefore, was not embraced by a majority. Although that argument had no further development in this area of law, its core idea, that the Eighth Amendment “must draw its meaning from the evolving standards of decency that mark the progress of a maturing society” (p. 101), has been accepted as a critical element of constitutional law relating to capital punishment (e.g., Gregg v. Georgia, 1976).
In Afroyim v. Rusk (1967), the Court overruled Perez and adopted Warren's broad argument that citizenship could only be voluntarily relinquished.
— Dean Alfange, Jr.
