By Lawrence Hurley
WASHINGTON (Reuters) - The Supreme Court on Monday weighed whether part of a tough federal criminal sentencing law should be struck down for being overly broad as the justices heard an appeal by a Minnesota white supremacist sentenced to 15 years in prison for illegally possessing a firearm.
Several of the nine justices indicated a willingness during the one-hour oral argument in the case to vote in favor of defendant Samuel Johnson, although it is unclear exactly how they will rule.
If Johnson wins, he would be re-sentenced, facing a maximum 10-year sentence instead of 15 years. If the court strikes down the provision in question, it would affect similar cases around the United States.
The law, called the Armed Career Criminal Act, imposes a minimum 15-year sentence when a defendant is convicted of possessing a firearm and has previously been convicted of at least three qualifying crimes, including violent felonies. The law outlines the crimes covered, including burglary and arson.
At issue in the case is an additional provision that says the law also applies to previous convictions that concern "conduct that presents a serious potential risk of physical injury to another."
Criminal defense lawyers say the phrase is too vague and violates the U.S. Constitution's Fifth Amendment, which mandates due process under the law. The Supreme Court has already had several cases in recent years touching upon what kind of conduct should be covered.
Johnson was hit with the additional sentence in 2012 when he pleaded guilty to one count of being a felon in possession of a firearm. He had previously been convicted of robbery on two occasions and possessing a short-barreled shotgun. Johnson's lawyers argued that merely possessing the shotgun should not count as a violent felony.
Johnson initially attracted the FBI's attention in 2010 due to his role with the National Socialist Movement, a white supremacist group.
During the oral argument, several justices gave potential examples of why the law could be viewed as overly broad.
Liberal Justice Stephen Breyer said the phrase could cover someone convicted of multiple drunken driving offenses. Conservative Justice Antonin Scalia questioned whether blackmail would be covered even if there is no explicit threat of violence.
"There's something odd about this statute that's causing the problem, and I can't put my finger on it," Breyer said.
A ruling is due by the end of June.
The case is Samuel Johnson v. United States, U.S. Supreme Court, No. 13-7120.
(Reporting by Lawrence Hurley; Editing by Will Dunham)