The battle over expanded American Indian gambling agreements has become one of the most expensive ballot initiatives in state history.

Those supporting and opposing the agreements have raised nearly $94 million.

Propositions 94 through 97 would allow four Southern California tribes, including the Pechanga band near Temecula, to add a total of 17,000 slot machines in exchange for giving a larger share of their revenue to the state.

Typically, campaigns raise from a few millions to as much as $20 million, said Kim Alexander, a political analyst.

The most expensive single ballot initiative campaign in the state was 2006's Proposition 87, which unsuccessfully sought to impose a $4 billion tax on oil companies to promote alternative fuels and energy-efficient vehicles.

It raised a total of more than $155 million from both sides.

By comparison, the $94 million raised on Props. 94 through 97 is more than the $93 million that tribes and their opponents raised in 1998 on Proposition 5, which legalized tribal gambling in California (though in today's inflation-adjusted dollars, Prop. 5's $93 million would be $118.3 million).

Prop. 5 was later ruled unconstitutional by the state Supreme Court, leading to a $69 million fight over Proposition 1A, which set the current rules for tribal gambling.

Political analysts say the reason that tribes are willing to wager such huge amounts is clear.

"If tribes are willing to spend tens of millions of dollars, there's got to be a lot more money at stake here," said Alexander, president of the watchdog group, California Voter Foundation.

There is, economists say.

California's tribal gambling industry generated an estimated $7.7 billion in 2006, according to Alan Meister, an economist with the Analysis Group consulting firm in Los Angeles.

Nevada casinos took in $12.6 billion the same year, according to Meister's "Indian Gaming Industry Report."

The tribes that stand to benefit from the new agreements are Pechanga, the Agua Caliente Band of Cahuilla Indians in Palm Springs, the Morongo Band of Mission Indians near Cabazon and the Sycuan Band of the Kumeyaay Nation in East County.

Under the agreements, the Agua Caliente and Sycuan tribes would get up to 5,000 slot machines each. The Morongo and Pechanga tribes would get up to 7,500.

Tribes throughout the state have a total of 60,000 slot machines and most tribes agreed to a limit of 2,000 machines each.

Proponents of the new agreements say there is an unmet demand for the slot machines, which generate most of the tribal casinos' profits.

They say the state and the tribes stand to benefit by expanding the number of machines.

"We would argue that the revenues that will be provided to the state will help (alleviate its budget woes) and local governments will also benefit tremendously," said Roger Salazar, a spokesman for the "yes" on Props. 94-97 campaign. "And yes, there's no question that the businesses will grow."

Together, the four tribes have raised more than $66 million to convince the voters that the agreements are good for the state.

Much of the money is spent on TV ads asserting that the state would receive more than $9 billion over the two decades that the agreements would be in effect.

But opponents, including a racetrack owner, a labor union and two tribes, say the agreements negotiated by Gov. Arnold Schwarzenegger and approved by the Legislature last year amounted to "sweetheart" deals for four of the most influential tribes in the state.

"Just four (of the state's 108) tribes would control one-third of the state's gambling pie," said Scott Mcdonald, a spokesman for the "no" on Props. 94-97 campaign. "It's not what we want."

For the opponents, the campaign is also about money and competitive advantage, said Tim Hodson, executive director of the Center for California Studies at Sacramento State University.

"You have gambling interests from Nevada and other forms of gambling, and for these interests, it's really an economic fight," Hodson said.

One of the main donors to the "no" campaign is Terry Fancher, owner of the Hollywood Park and Bay Meadows horse racetracks.

The racetracks have provided $6.8 million of the more than $27 million raised by the campaign.

Mcdonald said race tracks stand to lose business to expanded tribal casinos, as do other tribes with casinos, such as the Pala Band of Mission Indians in North County.

The Pala band and the United Auburn Indian Community contributed a total of more than $17 million to oppose the agreements.

Unite HERE, a labor union representing service industry workers, contributed another $3 million to the campaign. Union leaders have said that the agreements make it more difficult for casino workers to unionize.

Despite the financial advantage, the four tribes face an uphill battle, Hodson said.

"Traditionally, California voters are cautious," he said. "If there is any doubt in their mind, they will vote 'no.' "

Supporters of the agreements acknowledge that they have much work to do before the Feb. 5 vote.

A Field Poll released Dec. 27 reported that 28 percent of likely voters were undecided.

Only a slight majority 39 percent said they were inclined to vote "yes." Thirty-three percent of those surveyed said they were inclined to vote "no."

However, Salazar said he was confident the campaign would win over enough of the undecided voters.

"We feel pretty confident that the voters are going to approve these measures," he said.

Contact staff writer Edward Sifuentes at (760) 740-3511 or esifuentes@nctimes.com.