The Supreme Court on Monday declined to take a case about the boundaries of the Second Amendment's right to keep and bear arms, by saying it will not review a California self-defense law.

The petitioners in Peruta v. California who asked the Supreme Court to review the case called the controversy "perhaps the single most important unresolved Second Amendment question" left to come before the Supreme Court. The high court's action on Monday will leave that question unresolved.

The question the Supreme Court refused to hear is whether the Second Amendment gives people the right to carry handguns outside the home for self-defense, including concealed carry when open carry is forbidden by state law.

Justice Clarence Thomas dissented from the high court's decision not to take the case, which Justice Neil Gorsuch joined.

"At issue in this case is whether that [Second Amendment] guarantee protects the right to carry firearms in public for self-defense," Thomas wrote. "Neither party disputes that the issue is one of national importance or that the courts of appeals have already weighed in extensively. I would therefore grant the petition for a writ of certiorari."

He added, "For those of us who work in marbled halls, guarded constantly by a vigilant and dedicated police force, the guarantees of the Second Amendment might seem antiquated and superfluous. But the Framers made a clear choice: They reserved to all Americans the right to bear arms for self-defense. I do not think we should stand by idly while a state denies its citizens that right, particularly when their very lives may depend on it."

California law generally prevents carrying a handgun outside a home, but concealed carry is allowed for those with a license. Applicants for such a license need to demonstrate "good cause" to obtain the license, which several sheriffs have taken to mean including carrying a handgun for self-defense, as the petitioners noted in their brief to the Supreme Court. But in San Diego, the sheriff defined "good cause" as requiring a " particularized" need for self-defense that separates the applicant from an average applicant.

A three-judge panel found the San Diego County Sheriff's policy unconstitutional, but was reversed by the 9th Circuit Court of Appeals. Since the Supreme Court did not take the case, the 9th Circuit's ruling will prevail.

"We should have granted certiorari in this case," Thomas wrote. "The approach taken by the en banc court is indefensible, and the petition raises important questions that this court should address. I see no reason to await another case."

Paul Clement, an attorney who several conservatives hoped to see included on President-elect Trump's Supreme Court short lists when looking to replace the late Justice Antonin Scalia, is listed as the counsel of record for the petitioners challenging the California policy and 9th Circuit decision.