Proposition 38 would authorize the bonds and distribute the money to nonprofit research centers studying immunotherapy treatments for cancer, heart disease and Alzheimer's. The state would repay the debt at a cost of roughly $500 million a year for 20 years, including about $4 billion in interest, for a total tab of approximately $12 billion.

The measure's origins are unusual. It was conceived and bankrolled by Gary Michelson, a wealthy philanthropist who paid to gather signatures and place it on the ballot. Its language sets strict criteria for the institution that would receive half the money—criteria so specific that only UCLA qualifies. That half would launch a new immunology institute at UCLA, while the other half would be awarded through competitive grants to other California institutions, all coordinated through the same UCLA entity.

Michelson has already donated $120 million of his own money to establish the California Institute for Immunology and Immunotherapy at UCLA, the same institution that would be the hub for the bond-funded research.

Supporters include a long list of disease advocacy groups—Blood Cancer United, the Melanoma Research Alliance, the Alzheimer's Association, the ALS Association, the National Multiple Sclerosis Society and the Michael J. Fox Foundation for Parkinson's Research—that believe new immunotherapies could treat the conditions they champion. Proponents also argue that federal funding for such research has become unreliable under the current administration.

Jillian McCool, a researcher who studied vaccines and cancer therapies at Lawrence Livermore National Laboratory, said her work was upended when grants ran out and funding was paused during a government shutdown. About 100 scientists were laid off, including her, and she was out of work for a year and a half.

"All of a sudden we have this weird rhetoric around vaccines and all of a sudden there's this new administration coming in that's kind of pushing that rhetoric," McCool said. "And then the public is no longer trusting scientists and what they have to say in the data we've collected, it kind of makes you question your whole career in general."

McCool said Prop 38 would correct what is happening at the federal level and protect scientists' jobs. She noted the measure is designed to be cost-neutral, with 10% of revenues from successful discoveries funneled back to the state, and Californians entitled to a 20% discount on any new therapies developed with the bond money.

Laurie Adami, a Los Angeles resident diagnosed with non-Hodgkin's lymphoma 20 years ago, enrolled in a clinical trial for an immunotherapy called CAR-T. She received one infusion about eight years ago and her cancer has not returned. While she is only one patient and many trial participants did not respond the same way, she is a vocal supporter of the measure.

"Not every family is gonna be affected by cancer, but every family is gonna [be] affected by these other diseases," Adami said. "And so I am a huge proponent and supporter because immunotherapy saved my life. So why wouldn't I believe? And why wouldn't I want more patients to be able to access the type of treatment that finally saved my life?"

Opposition is small and grassroots, led by Robert Kaplan, a biomedical researcher and administrator at Stanford University School of Medicine who previously worked at the National Institutes of Health. Kaplan said he supports immunotherapy research but objects to the measure's structure.

"If you look at NIH support for biomedical research in general or immunology research, there are several institutions in California that are the national leaders, but because of the sort of arbitrary criteria in Proposition 38, they're not eligible to compete," Kaplan said. "And we think that's not right."

Science grants are typically awarded through open competition based on proven track records, Kaplan said, and spreading research across institutions fosters diverse ideas and methods. Under Prop 38, half the money goes directly to a brand-new institute with no track record.

"I think [if] taxpayers are going to have to repay these bonds, we think that should be a fair competition that allows all of these excellent institutions in California to have an opportunity to be in that competition," he said.

Critics also note the measure is limited to immunology and immunotherapy, excluding other health priorities such as mental illness or kidney disease.

Three retired analysts from the nonpartisan Legislative Analyst's Office have broken with the agency's tradition of neutrality to oppose the measure. Dan Carson, who ran the LAO's health section in 2004 when voters approved a $3 billion stem cell research bond, said that measure's promised payback never materialized.

"In fact, as our analysis at the time made really clear, the state eventually received only a tiny fraction of the billions of dollars we were promised," Carson said. "So here we go again with Prop 38."

Carson, a cancer survivor, rejected the cost-neutral claim. "Once again, we're being promised in this initiative and by its advocates that [it] will, quote, pay for itself with no net cost to the state or taxpayers, closed quote," he said. "I'm here to tell you that after reviewing the fine print of this ballot measure, that won't happen."

The Yes on Prop 38 campaign has raised about $27 million, mainly from Michelson and another billionaire who have donated to the same UCLA institute that would be the primary beneficiary. The No side has raised no money.

A yes vote means the state could borrow $8.4 billion for immunology and immunotherapy research. A no vote means it cannot.