The United States Court of Appeals for the Ninth Circuit’s Courtroom 3 - a miniature auditorium with comfortable, smoked salmon-colored seats - was mostly filled with law students who seemed to be interested in just one thing: listening to Harvard Law School Professor Laurence Tribe argue constitutional law.

It was a rare treat for law students, and they weren’t disappointed. Tribe, nationally recognized as one of the foremost liberal constitutional law scholars and Supreme Court practitioners, was in town from his lucrative gig as a consultant to the international law firm Akin Gump Strauss Hauer & Feld to give oral arguments in the billboard case Metro Lights v. City of Los Angeles.

Tribe, dressed in a gray suit and wearing a bright blue tie, told the Weekly that he became involved in the case just a month ago because it “intrigued me” and “I thought the federal court was clearly right.”

Tribe has successfully gone before the U.S. Supreme Court over 17 times.

In addition to Tribe’s First Amendment wins, he authored American Constitutional Law (1978), the most commonly cited work in that field, and in 2001 he co-founded the liberal American Constitution Society, supposedly to counterweight the conservative Federalist Society.

Tribe is also the official legal adviser to the Barack Obama campaign. His most infamous case is Gore v. Bush in 2000.

“I turn down a great majority of cases,” added the energetic gray-haired professor. Why did he take the case? “Because I think the L.A. ordinance is a serious threat to the First Amendment and needs to be decisively invalidated.”

Unfortunately for anti-billboard activists sick of the proliferation of advertising citywide, it seemed like at least one judge agreed. “[Judge Richard C.] Talman was nodding the whole time when Tribe spoke,” said one billboard activist. “[The judges] obviously respect him a great deal,” said another.

City Attorney Rocky Delgadillo is hoping that the panel of three judges will overthrow a 2006 district judge’s ruling that its “Street Furniture” program is unconstitutional. A ruling against the city by the Court of Appeals could spell disaster for City Hall’s 2002 ban on all new billboards.

The implications are huge, say billboard critics who fear that a lifting of the 2002 billboard ban will open up the floodgates to a never-ending stream of new billboards, in a city already blanketed by roughly 4,000 illegal billboards and thousands of legal ones.

The case now before the court dates to 2001, six months before City Hall passed a blanket ban on all new billboards, when the city entered into a contract with CBS Decaux, which gave CBS a lucrative contract to sell and display miniature billboard-style advertising on bus shelters and kiosks. In return, the city would get $150 million over the 20-year-term of the agreement.

Instead, the contract opened up a Pandora's box of litigation. It didn't take long before a private firm with no such deal with City Hall, Metro Lights, began putting up “movie poster”-style signs that look like the city's own “street furniture” small billboards.

In 2003, the city began citing the company for illegally erecting billboards. Metro Lights filed a federal lawsuit against the city arguing that it was unfair that the city could make money off its 3,300 street furniture advertising program, tens of thousands of street banners and countless wall signs, murals and super graphics on public property but forbid similar advertising on private property by a private firm. In 2006, a district judge agreed.

Today's oral arguments were short and to the point. Both sides were given 20 minutes to argue in front of Senior Circuit Judge David R. Thompson, and Circuit Judges Diarmuio F. O’Scannlain and Richard C. Talman.

Softspoken Deputy City Attorney Ken Fong argued first that the district court made an error in its earlier findings that the city’s “Street Furniture” program was unconstitutional. The slight Fong said that the city had every right to ban commercial signs and profit on its own "transit aesthetic" program.

Fong’s animated argument didn’t seem to convince Judge Talman, who stated that the city was discriminating against other billboard firms. “The city is in competition with other outdoor advertisers and is exempting itself,” he said. “And is denying the right to other advertisers that it is granting itself.”

Backing City Hall's efforts was CBS attorney Laura Brill, sporting a black suit and sitting at the same table as Fong.

The dark-haired, attractive Brill helped negotiate Clear Channel Outdoor's and CBS Outdoor’s “sweetheart” settlement deals with City Hall, which allowed those billboard giants to digitally enhance over 800 billboards. In this case, it is clear that CBS doesn’t want to lose its monopoly on billboards here, which could happen if the 2002 billboard ban is lifted.

Tribe, a spunky, scruffy-haired, fast-talking man in his late 60’s, argued that the city’s 2002 ban on billboards restricted free speech and gave City Hall an unfair advantage in outdoor advertising.

“Our first amendment rights are not for sale,” he argued. “The government cannot through a contract six months before the ban override constitutional rules. The government through its contract cannot override constitutional principles.”

If he wins “the ban would be gone,” said Tribe as he quickly made his way out of the courtroom, his admirers trailing behind. He was leaving Los Angeles immediately to return to Harvard for the university's commencement on Thursday. “The city is auctioning off First Amendment rights. They are giving preferential treatment to some billboard companies over others.”

We will soon see. A ruling on the case should take a few months.

Contact reporter Christine Pelisek at cpelisek@laweekly.com