By contrast, advocates of gun rights praised the decision, by the United States Court of Appeals for the District of Columbia Circuit, saying it raised the prospect of a national re-evaluation of the meaning of the Second Amendment and the rights of gun owners. They said the District of Columbia would have to begin procedures to allow handgun possession in private homes unless yesterday's decision was stayed.

Lawyers on both sides of the case said it had created a conflict among the federal courts of appeal on a significant constitutional issue, making review by the Supreme Court likely. The Supreme Court last considered the issue in 1939, and there are only scattered hints about how the current justices might rule.

