WASHINGTON -- The Supreme Court yesterday appeared split along familiar ideological lines over whether sentencing a juvenile to life in prison without the possibility of parole for a nonhomicide violates the Constitution's prohibition of cruel and unusual punishment.

The court in 2005 decided that it was unconstitutional to execute juveniles who had committed murder. Now, advocates for youthful offenders are asking the court to declare that sentencing juveniles convicted of nonlethal crimes to "die in prison" should also be forbidden.

Attorney Bryan Gowdy, who represents a man who was sentenced to life without parole at age 17, told the justices that his client and others imprisoned as juveniles deserve a right to prove that they have changed. He said his client, Terrance Graham, now 22, seeks a "meaningful opportunity" at some point to show that he is "fit to live in society. That's all -- that's all we're asking for."

Mr. Graham was sentenced after he violated his probation by taking part in a home invasion. A year earlier, he had been convicted of armed robbery.

The justices also heard a second case from Florida. Joe Harris Sullivan, now 34, was one of only two 13-year-olds in the nation to receive the sentence -- in his case, for two counts of sexual battery. The lawyers said such sentences violate the Eighth Amendment, an argument that found little favor with the court's more conservative justices.

Chief Justice John G. Roberts Jr., along with Justices Antonin Scalia and Samuel A. Alito Jr., wondered what part of the Constitution allowed them to make the distinctions the lawyers made between the culpability, for instance, of a 17-year-old and an 18-year-old.

Chief Justice Roberts suggested that it would be more palatable to make sure that judges take the age of defendants into account when imposing such harsh sentences, and that the sentences then could be reviewed for whether they were disproportionate to the crime. Justice Alito said some of the crimes committed by juveniles were so horrible that he could hardly believe that they had occurred, and he said states should have the option to impose life without parole.

Justice Ruth Bader Ginsburg said Chief Justice Roberts's idea would not solve the basic problem: that juveniles are still developing and are not fully culpable for their actions. Decisions about whether they have reformed can be made only at a later date, she said.

Mr. Sullivan's lawyers renewed their efforts on his behalf after the court's 5-4 ruling in 2005 that executing juveniles violated the Eighth Amendment. Justice Anthony M. Kennedy wrote in that decision that the immature actions and developing nature of juveniles mean that "it is less supportable to conclude that even a heinous crime committed by a juvenile is evidence of irretrievably depraved character." He added: "It would be misguided to equate the failings of a minor with those of an adult, for a greater possibility exists that a minor's character deficiencies will be reformed."

But Florida and 19 other states said they should retain the right to decide how to sentence those who commit crimes, regardless of age. "There is no consensus against life sentences for juveniles, particularly for heinous crimes such as sexual battery," Florida Solicitor General Scott Makar told the court in the state's brief.

Pennsylvania leads the nation with more juvenile lifers than any other state; in May 2008, the state had 444. But all of Pennsylvania's juvenile lifers were convicted of first- or second-degree murder.

Washington correspondent Daniel Malloy writes the "Pittsburgh On The Potomac" blog exclusively at PG+, a members-only web site of the Pittsburgh Post-Gazette. Our introduction to PG+ gives you all the details.