The court will sooner or later return to the subject of the scope of the Second Amendment right first recognized in 2008 in District of Columbia v. Heller, which struck down parts of an exceptionally strict local law that barred keeping guns in the home for self-defense. But the justices do not seem eager to do so even as the nation is in the midst of a sharp debate over gun control in the wake of shooting rampages in San Bernardino, Calif., and across the nation.

In dissent on Monday, Justice Clarence Thomas, joined by Justice Antonin Scalia, accused the court of abdicating its responsibility to enforce the constitutional right to keep and bear arms. (Justice Scalia wrote the majority opinion in the Heller case, which was decided by a 5 to 4 vote.)

“Roughly five million Americans own AR-style semiautomatic rifles,” Justice Thomas wrote, referring, he said, to “modern sporting rifles.”

“The overwhelming majority of citizens who own and use such rifles do so for lawful purposes, including self-defense and target shooting,” Justice Thomas wrote. “Under our precedents, that is all that is needed for citizens to have a right under the Second Amendment to keep such weapons.”

Chuck Michel, president of the California Rifle and Pistol Association, said the dissent made powerful points. “It is only a matter of time,” he said, “before the Supreme Court takes a case, sets things straight, and properly subjects this and similar unconstitutional laws to renewed challenge.”