The U.S. Supreme Court on Monday expanded the reach of the Second Amendment to the states, opening the door to challenges of local handgun laws across the country.

In McDonald v. Chicago, a 5-4 majority said that a handgun ban in Chicago may have violated Second Amendment rights established in the Court’s landmark 2008 decision in District of Columbia v. Heller. Justice Samuel Alito Jr., who delivered the majority opinion for the Court in McDonald v. Chicago, wrote that the right to keep and bear arms is “among those fundamental rights necessary to our system of liberty.” Alito’s 45-page opinion said the right is fully binding on the states — a move limiting, but not eliminating, local and state efforts to craft measures to combat social problems.