The North County community is an original member of the Orange County Regional Airport Authority, a group of cities that supports the conversion. But voters in the city elected anti-airport activist Carolyn V. Cavecche to their City Council earlier this week, which means three of the body's five members now oppose the conversion plans.

Cavecche wasn't available for comment Thursday, but Orange councilman Mike Alvarez—who also opposes the airport idea—says the city may soon yank its support from the coalition. "I think we could pull out [of the Airport Authority] within the next 30 days," he says.

Such a defection would deal a serious blow to the power of the Airport Authority, which was created to provide a unified voice for cities that would be impacted by a base conversion. Officials in nearby Villa Park dropped out in April, and Fullerton's City Council took preliminary steps to withdraw earlier this week.

The coalition has been crumbling, in part, because its members cannot agree on the proposed airport's take-off and landing patterns. While all of the cities would welcome the regional economic benefits a conversion would provide, few are willing to put up with more traffic in the skies above their respective communities.