Supporters of the state's first proposed urban casino said Saturday that Casino San Pablo will bring jobs and revenue to a struggling city while opponents argued that it will drain money from local residents' pockets while creating traffic nightmares and social problems.

More than 400 people packed a standing-room-only public hearing on the plan at Contra Costa Community College.

Organizer Assemblywoman Loni Hancock, D-Berkeley, said local residents and community leaders have been left out of the process in which Gov. Arnold Schwarzenegger crafted a gaming compact with the Lytton Band of Pomo Indians to turn their current cardroom off Interstate 80 into a casino. The proposal has been stalled since August in the Legislature, which must approve the compact.

Since the controversial compact was announced, the tribe has halved the number of proposed slot machines to 2,500, and leaders said they will unveil a new, scaled-back plan within a month.

"Our casino will not be a Las Vegas-style establishment dropped into the middle of San Pablo," said tribal chairwoman Margie Mejia.

While the Legislature weighs the proposed compact, Sen. Dianne Feinstein is hoping to kill the deal by reintroducing legislation Monday that would reverse a controversial amendment by Rep. George Miller, D-Martinez, that turned the cardroom into a reservation for the Lytton and allowed them to seek a full-fledged casino.

Despite strong support from the city of San Pablo leaders and the union representing casino workers, residents and leaders of nearby cities are concerned about the traffic, public safety impacts and social ills a casino could bring to the region. They also worry about access to Doctors Medical Center, adjacent to Casino San Pablo.

The tribe has pledged to share an unprecedented 25 percent of its gaming profits, which it estimates at $155 million a year, with the state and local governments to mitigate problems.

But a traffic engineer hired by casino opponents said it could cost more than $90 million and take 10 to 20 years to widen Interstate 80 and make changes to San Pablo Dam Road, leading to the site.

The engineer, Arnold Torma, estimated that a casino with 2,500 slot machines would increase traffic on I-80 -- already one of the worst commute routes in Bay Area -- by 10 percent. Traffic on San Pablo Dam Road would more than double.

The tribe, meanwhile, estimates the new casino would create more than 6, 000 unionized jobs with good wages and benefits.

San Pablo City Manager Brock Arner said such jobs are needed in a city where 18 percent of the population lives in poverty and unemployment is 237 times higher than the county average.

Already, the cardroom contributes 15 percent of the city's general fund and has helped pay for police, a health clinic, and youth and senior citizen programs.

"If this proposal doesn't proceed, I think the city of San Pablo will implode financially," he said.

Arner presented Hancock, who opposes the casino, with petitions from 1, 700 local residents supporting the casino. But Hancock said 91 percent of constituents she surveyed by mail were opposed, including 65 percent of San Pablo residents. Of the 153,000 households contacted, 10,000 responded.

William Thompson, a professor at the University of Nevada, Las Vegas, said that the casino would not help the region's economy because the gamblers would be local people who could spend their money on other things.

He likened the casino not to those on the Las Vegas strip, where 95 percent of gamblers are tourists, but to slot machines in grocery stores played by locals.

"Your economy loses," he said. "Urban casinos do not make sense."

Other speakers warned that the Casino San Pablo deal should be considered in conjunction with proposals for Indian casinos in Richmond and Oakland.

"There are nearly six tribes all talking about and promising a lot of money. I'm skeptical that they all can deliver," said Oakland City Councilwoman Jean Quan, among local leaders who bemoaned the lack of local control over casino proposals.

Fairfax City Councilman Frank Egger said he is working on a proposed constitutional amendment to Prop. 1A, which legalized casinos on Indian land in 2000, that would enact a five-year moratorium on new casinos.

Casino opponents outweighed supporters among the public speakers. Among them was Carol Manahan of Richmond, who lives near Casino San Pablo. She said she has been solicited for prostitution and had two women come to her door late at night asking for money because they'd lost theirs in the cardroom.

But Arnie Kasendorf of Richmond, who leads senior bus trips to Nevada and Indian casinos, said he welcomes the casino.

"(The tribe) will have the income, and we seniors will have an exciting place to spend some time without long hours on the bus," he said.

Casino San Pablo

San Pablo voters invited gamblers to their city 10 years ago in hopes of generating income. Here's a look at the city, the current casino and the proposed enlarged casino.

THE CITY

Size: 2.6 square miles

Population: 30,215

Median per-capita income: $14,303

THE CASINO

Size of current Casino San Pablo cardroom: 71,000 square feet

Number of card tables: 40

Number of proposed slot machines: 2,500

Sources: U.S. Census; Governor's office; Casino San Pablo; ESRI; GDT

E-mail Janine DeFao at jdefao@sfchronicle.com.