The Court ruled that the Eighth Amendment's Cruel and Unusual Punishment Clause allowed a state to impose a life sentence without the possibility of parole for the possession of 672 grams (23.70 oz) of cocaine.

The only aspect of the decision that garnered the vote of five Justices was the ultimate conclusion that the mandatory life without parole sentence required by the Michigan law forbidding the possession of more than 650 grams of cocaine was not cruel and unusual punishment.

Justice Antonin Scalia, as is typical of his originalist interpretation of the Constitution, introduced historical evidence in support of his argument that the Eighth Amendment imposes no proportionality requirement at all.

Justice Anthony Kennedy argued in favor of a vague proportionality principle that allowed the Court to uphold Harmelin's sentence.

For Scalia, though, the more important question was what the words "cruel and unusual" meant to the Framers of the Bill of Rights in 1791 when the Eighth Amendment was adopted.

"There is little doubt that those who framed, proposed, and ratified the Bill of Rights were aware of such provisions [outlawing disproportional punishments], yet chose not to replicate them."

As for whether other jurisdictions imposed a lesser sentence for the same crime, Scalia conceded that it is easy to figure this out, but that this inquiry has "no conceivable relevance to the Eighth Amendment."

"The Eighth Amendment is not a ratchet, whereby a temporary consensus on leniency for a particular crime fixes a permanent constitutional maximum, disabling the States from giving effect to altered beliefs and responding to changed social conditions."

Accordingly, the Eighth Amendment imposed a strong proportionality requirement not simply on fines, but on all criminal punishments, including prison terms.

Second, although the newly formed federal government did not, in 1791, have any "track record with respect to criminal law," they had lived under the regime of the several states for some time, and so there would be some benchmarks by which to evaluate proportionality of punishments.

White's argument proceeds from the premise that "the scope of the prohibition against cruel and unusual punishments has long understood the limitations of a purely historical analysis."

The Court therefore has recognized that a punishment may violate the Eighth Amendment if it is contrary to the evolving standards of decency that mark the progress of a maturing society.

In evaluating a punishment under this test, we have looked not to our own conceptions of decency, but to those of modern American society as a whole in determining what standards have evolved, and thus have focused not on the subjective views of individual Justices, but on objective factors to the maximum possible extent."

White also argues that adopting Scalia's view of the proportionality requirement would strike at the foundation of the Court's capital punishment jurisprudence, much of which would then "rest on quicksand".

Justice Kennedy argued that "stare decisis counsels our adherence to the narrow proportionality principle that has existed in our Eighth Amendment jurisprudence for 80 years."

First, "the fixing of prison terms for specific crimes involves a substantive penological judgment that, as a general matter, is properly within the province of legislatures, not courts."

In Solem, the Court struck down a life-without-parole sentence imposed for the crime of uttering a no-account check; Harmelin, however, was convicted of possessing 650 grams of cocaine.

In view of these observations, a legislature could rationally conclude that a life sentence without parole is appropriate to deter others from distributing cocaine and to achieve an appropriate amount of retribution.

For Justice White, Kennedy's narrow proportionality principle effectively "eviscerates" Solem, leaving only an "empty shell" in its place.