By JESS BRAVIN (Wall Street Journal)

A federal appeals court in Chicago ruled Tuesday that the Second Amendment doesn't bar state or local governments from regulating guns, adopting the same position that Judge Sonia Sotomayor, President Barack Obama's nominee to the Supreme Court, did when faced with the same question earlier this year.

Last year, the U.S. Supreme Court cited the Second Amendment to strike down a handgun ban adopted in 1976 by the Washington, D.C., City Council. The court, by a 5-4 vote, found that the amendment protected from federal infringement an individual right to "keep and bear arms."

The decision applied only to the District of Columbia, a federal enclave that is not a state. It left open whether the amendment also limits the powers of state government.

A string of 19th century Supreme Court decisions limited application of the Bill of Rights to state governments. During the 20th century, the Supreme Court held that certain constitutional rights, but not the Second Amendment, could be enforced against the states.

Gun-rights groups challenged ordinances in Chicago and Oak Park, Ill., as unconstitutional in light of the Supreme Court's decision last year. A federal district judge rejected their arguments, a decision affirmed Tuesday by the Seventh U.S. Circuit Court of Appeals.

Writing for a three-judge panel, Judge Frank Easterbrook observed that an 1886 Supreme Court decision limited the Second Amendment to the federal government. While that decision might be a "fossil," the lower courts have no power to overrule a Supreme Court opinion even if they suspect the high court may be inclined to do so itself. It was "hard to predict" what the Supreme Court would do should it consider the question in future, Judge Easterbrook wrote.

Judge Easterbrook and the two other Seventh Circuit judges were all appointed by Republican presidents. Judge Easterbrook wrote that they agreed with an unsigned Second Circuit opinion that in January rejected a Second Amendment challenge to a New York state law barring possession of nunchuka sticks, a martial arts weapon. That panel, in New York, included Judge Sotomayor and two other judges appointed by President Bill Clinton.

In San Francisco, however, a Ninth Circuit panel earlier this year held that the Second Amendment applies to state governments, even as it upheld a local ordinance banning guns from county property. One judge was appointed by a Republican president, the other two by Democrats.

Were they to follow the Ninth Circuit's reasoning, Supreme Court "decisions could be circumvented with ease," Judge Easterbrook wrote. "They would bind only judges too dim-witted to come up with a novel argument."

The split among the circuits increases the likelihood that the Supreme Court will step in decide the Second Amendment's application to state weapons laws.

If confirmed to the Supreme Court, Judge Sotomayor would not be bound by prior high court decisions and could provide her own analysis of the Second Amendment's application.

Write to Jess Bravin at jess.bravin@wsj.com