"The problem with your argument is that any time the government bans the sale of anything, it becomes a First Amendment issue," Kozinski told Collins.

The ordinance, the first of its kind in the nation, prohibits sales of cigarettes and other tobacco products at San Francisco's nearly 60 drugstores. It exempts supermarkets and big-box retail stores that also have pharmacies, the basis of a separate suit by Walgreens claiming unconstitutional discrimination.

A San Francisco Superior Court judge denied Walgreens' request for an injunction to keep the ban from taking effect. A state appellate court is preparing to hear the company's appeal.

Philip Morris also sued unsuccessfully to halt the ordinance. U.S. District Judge Claudia Wilken of Oakland ruled in December that San Francisco was free to prohibit conduct, such as tobacco sales, and was not trying to regulate speech.

The appeals court did not say when it would rule on Philip Morris' appeal of Wilken's decisio