A city lawsuit that seeks to implicate gun manufacturers in the trafficking of illegal guns faced a test today when opening arguments were made in a federal appeals court.

The case heard in 2nd Circuit U.S. Court of Appeals will decide if the lawsuit is constitutional after Congress passed legislation in 2005 meant to squash the case.

Last year, President Bush signed the legislation, the Lawful Commerce in Arms Act, which was meant to ensure that gun manufacturers couldn’t be held accountable for crimes committed with guns they sold.

New York contends that the law surpasses Congress’s power to regulate state and federal courts.

“There is a war on the judiciary here,” New York’s corporation counsel, Michael Cardoza, said.

The lawsuit became a point of conversation today for Republican presidential hopefuls who spoke to a gathering of the National Rifle Association, lobbying for an important presidential endorsement.

Senator McCain lambasted the city’s lawsuit, describing it as “a devious attempt to bankrupt gun owners.”

Seeking to reshape a checkered reputation with gun rights advocates, Mayor Giuliani said he thought the New York lawsuit had gone in the wrong direction since it was first lodged during his tenure as mayor.

Mr. Giuliani once called the NRA an “extremist” group, but he has been vocal during the presidential race about his support of the second amendment.

A spokesman for the gun rights group National Shooting Sports Foundation, Lawrence Keane, said Mr. Giuliani is trying to “camouflage” his record on guns.

“His support for gun control and contempt for the manufacturers, retailers and purchasers of firearms may have gained him praise in Gotham, but that will only handicap him in the rest of the country,” he said. “He understands this and is now trying to backpedal.