SACRAMENTO — As a legislative deadline loomed, California senators Thursday — in some cases, reluctantly — voted to pass a $400 billion plan to create a government-run health care system without a way to pay for it.

Senate Bill 562, by Sens. Ricardo Lara, D-Bell Gardens, and Toni Atkins, D-San Diego, passed 23-14 and will now advance to the Assembly, where it will likely be amended to include taxes. And that would mean the measure would require two-thirds votes in both chambers.

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Editorial: Single payer detracts from pressing California health care issue “What we did today was really approve the concept of a single-payer system in California,” Lara said in an interview after the vote.

The California Nurses Association, the bill’s lead sponsor, has pushed the proposal hard, organizing demonstrations at the California Democratic Convention last month and promising to “primary” incumbent Democrats who don’t jump on board. On Wednesday, a study commissioned by the nurses concluded that Californians could save tens of billions of dollars annually under such a system through lowering of drug prices and elimination of administrative overhead.

Most California families and businesses, the University of Massachusetts study said, would pay less for health care than they do now, even with the new taxes, because they would no longer pay premiums, deductibles or co-pays.

A Senate committee analysis released last week, however, estimated that the state would have to raise $200 billion in revenue each year, which it said could be done through a 15 percent payroll tax.

Republicans argued forcefully against the bill, questioning its cost and the very idea of a government-run program.

“How do we possibly pay for this thing?” asked Sen. Tom Berryhill, R-Oakdale.

Sen. John Moorlach, R-Costa Mesa, said he felt like he was in the car with “Thelma and Louise.”

“Colleagues, cliff dead ahead,” he said.

Lara acknowledged the bill was “a work in progress.” One of the many big questions left unanswered in the thin, 38-page proposal is whether the federal government would permit California to use existing Medicare funding for such a plan. The state also doesn’t know whether Congress will slash health care funding by repealing the Affordable Care Act.

It’s also possible that voters might need to approve such a change because of a rule called the “Gann Limit,” a 1979 statewide measure approved by voters that limits the growth in spending of the state and local governments.

The vote put Democrats in an awkward position, and a number of lawmakers made that clear on the floor.

Sen. Ben Hueso, D-Chula Vista, said he could not support the proposal because it lacked so much detail that if it passed, the Senate would be “kicking the can down the road” to the Assembly, where, he predicted, it would die.

“The people of our state deserve a more substantive discussion,” he said. “I don’t know what I’m voting on.”

Fellow Democrat Sen. Richard Pan, a pediatrician from Sacramento, also withheld his support, saying he wasn’t comfortable voting for the bill in its current form. And Sen. Steve Glazer, a moderate Democratic from Orinda, called it “premature.” He argued that the best course was to hold off on the vote, “finish the policy work” and put the proposal on the ballot in 2018.

But Lara said lawmakers needed to keep the momentum going. He emphasized, however, that that doesn’t mean that the University of Massachussetts study won’t be scrutinized. He said he’s not going to try to jam the bill through in one year if it’s not ready.

“The last thing I want to do is to create another financial burden on the state,” Lara said.

Sen. Nancy Skinner, D-Oakland, argued that a single-payer plan “may be a necessity. We may be

faced by circumstances where our health system as we know it is decimated by actions from D.C.”

Sen. Bob Hertzberg, D-Van Nuys, conceded that the bill — facing a Friday deadline for clearing the Senate — was “not cooked.” Legislative deadlines put senators in a tough position, he said, by forcing them to either kill the measure or “say I’m going to hold my nose” and pass it to the other house, despite its enormous questions.

But, he said, he came down in favor of the proposal.

“We have a lot of work to do. This is going to be hard,” Hertzberg said. “But it is necessary, and it is necessary because the system is upside-down.”