This morning Mayor Adrian Fenty announced that he would appeal a March ruling that found that the District’s handgun law was unconstitutional to the U.S. Supreme Court. His decision sets up the first major battle in decades over whether the Second Amendment confers an individual or collective right to own a handgun. Moreover, it could have a profound effect on gun regulations across the country should the Supreme Court side with the lower court.

The U.S. Court of Appeals for the D.C. Circuit ruled in early March that the District’s handgun ban was unconstitutional, and it turned down an appeal two months later. Since then, Fenty and his advisers have debated whether or not to appeal. The appeal allows the District’s three-decade-old handgun ban to remain in place pending any action by the Supreme Court — but at the same time also gives the new conservative majority on the court a chance to recast the debate over gun ownership and regulations.

District Attorney General Linda Singer announced that she would file a motion for a 30-day extension, allowing city officials to present their formal appeal to the Supreme Court after Labor Day.