Dr. Jonathan Fielding, the county health officer, wrote in a report this summer that it would be challenging to identify "underground, inconspicuous, intentionally noncompliant filmmakers."

County lawyers also said they worried the measure violated the 1st Amendment.

Weinstein charged that the real issue for county supervisors was disgust with the world of pornography.

Their rejection led him to take the issue to the ballot box, where, the public did not evince any of the government's qualms, he said Wednesday.

"There was no 'ick factor' among the voters. They were so much far ahead of the politicians. And they made a considered decision," Weinstein said.

He said the county’s worries about enforcement were silly and reflected officials' distaste for anything related to adult entertainment.

"If you have a hot dog stand, you apply for a permit and periodically a health inspector comes out and determines whether you're operating safely, so you don't give food poisoning to people," Weinstein said. "We have 134 businesses that require county permits. Why is this so exotic?"

He noted that the county has required sex clubs and bathhouses to obtain government permits since 2006.

Supervisor Michael D. Antonovich, who had remained silent on the law, declared his support for it Wednesday.

"It’s a matter of public health when you have the spreading of disease," Antonovich said.

The porn industry vowed to continue battling the law and made the economic impact on the region a central argument.

About 5,000 adult films are shot each year in the county, employing more than 10,000 people according to industry estimates.

Steven Hirsch, founder of the adult film company Vivid Entertainment Group, said the industry would fight the measure "to the very end" and predicted efforts to enforce the law would be an expensive failure.

"The truth of the matter is I'm not sure there will be a lot to enforce if no one is producing in the county of Los Angeles," he said, adding that supervisors would "spend a lot of time and a lot of money on how to figure out how to put something in place that ultimately won't work."

Evidence of how closely the porn community was following the vote could be found on an industry website where images of scantily clad women appeared next to breathless vote tallies from the county registrar-recorder’s office.

"The margins have closed slightly, though, as more returns have been posted to the official government website," AVN.com reported, adding, "Oh, and President Obama was re-elected."