The case of Christopher Simmons, who committed a capital crime between the ages of 15 and 18, is being reviewed by the Supreme Court to determine whether the death penalty is a disproportionate punishment for juveniles. The Missouri Supreme Court previously ruled that executing a juvenile who was under 18 at the time of the crime is unconstitutional, citing a national consensus against executing juvenile offenders. The petitioner argues that there is no consensus against capital punishment for juveniles, but the Supreme Court recognizes a consensus that juveniles are less culpable than the average criminal due to their lack of maturity and an underdeveloped sense of responsibility. The Supreme Court is considering whether the differences between juveniles and adults make it inappropriate to impose the death penalty on juveniles.

The interpretation of the Eighth Amendment should adjust to changing standards of decency, and it is not permanent. It may be debated how quickly these changes occur, but it is clear that the Constitution's understanding evolves over time. The Supreme Court's decision aligns with the views of respected lawyers from the past, such as Alexander Hamilton. The previous interpretation by the lower court would have allowed for the execution of 7-year-old children, but this is now considered immoral due to changing standards of decency. The lower court's mistake was not acknowledging the fact that the interpretation of this Amendment evolves over time.

The dissenting opinion disagrees with the Court's decision to ban the execution of offenders who committed a crime before turning 18, arguing that a clear national consensus against it does not exist. The Eighth Amendment prohibits cruel and excessive punishments, and the death penalty must be tailored to the nature of the crime and the defendant's personal responsibility. The Constitution requires an assessment of whether the death penalty is excessive punishment for a particular offense or class of offenders. The judge disagrees with the Supreme Court's application of Eighth Amendment principles to the current case, arguing that the Court should have addressed the lower court's erroneous ruling that a controlling decision was no longer valid due to outdated societal values. The Court looks to the actions of the nation's legislatures as the clearest and most reliable objective evidence of contemporary values. The Court has the power to overturn its own previous decisions to maintain consistent and coherent constitutional standards.

Justices Scalia and Thomas dissented from the majority's decision to prohibit the execution of murderers under 18, arguing that it is not consistent with the original meaning of the Constitution and the traditional role of the judiciary. They criticized the reliance on a "national consensus" to determine the constitutionality of the death penalty for juvenile offenders and suggested that legislative bodies, not courts, are responsible for reflecting the moral values of society. The use of scientific and sociological studies is criticized as problematic, and judges may lack the ability to make legislative judgments. The Court's decision to prohibit juries from considering a defendant's youth as a mitigating factor in capital sentencing has been criticized for being a threat to the capital sentencing system. The Court has also been criticized for prioritizing international views over those of US citizens, which aligns with treaties that the US has not ratified. The inconsistent use of foreign law in the Court's decisions is seen as an illegitimate form of reasoning that may lead to the Court imposing its own preferences on the American legal system.