Both Hollywood and the San Fernando Valley want out of L.A., and are demanding secession. After decades of idle threats and false starts, the measure is on the November ballot and it could have drastic consequences for the nation's second-largest city.

"Cityhood will mean smaller, more representative government," Richard Katz, of the Valley Independence Committee, said.

Katz said he wants "the neighborhood to decide whether or not you need some mini-mall on the corner, not some power broker downtown who doesn't live in your neighborhood, care about your neighborhood or even know where it is."

But the power brokers, who normally don't get along, are waging a mighty battle.

L.A. Mayor James Hahn, former Mayor Richard Riordan and basketball legend Magic Johnson are among dozens of high-profile people fighting what they call a disaster waiting to happen.

They warn secession would cost Los Angeles nearly 1 million people, its status as the nation's second-largest city and a lot of political influence. Many residents of both Hollywood and the Valley apparently agree because the secession measures are now running behind in the polls by a 3-to-2 margin.  

"There are so many unknowns in terms of what the costs are going to be," Laura Chick, L.A. city controller, said. "There is one certainty. There will be a lot of pain and a lot of problems for five to 10 years. Why not stay the great city, the world-class city that we are, and work together?"

But opponents are not as willing to roll the dice -- they're spending millions fighting because they risk losing billions. The San Fernando Valley generates some of the country's largest tax revenues and Hollywood makes L.A. more marketable to the rest of the world.

Secession would also mean L.A. would have less clout in Congress. The city now has 13 congressional members -- which is more than most states have -- but that number would drop by at least four -- and political experts say that would mean more trouble getting support for local projects.

"I don't thinks it's going to be a panacea overnight," said Katz. "Nothing's easy, but you don't make great gains unless you take big risks."

Fox News' Trace Gallagher contributed to this report.