Former Secretary of State George Shultz (search) on Tuesday became the most prominent Republican to endorse a $3 billion California ballot measure that would fund human embryonic stem cell research in the state.

"I don't think of it as an ideological or a political matter," Shultz said. "It's a matter of scientific research."

Former first lady Nancy Reagan (search) and several Republican lawmakers have called on the Bush administration to loosen its funding policies regarding stem cell research but haven't taken a public position on the California ballot measure.

Gov. Arnold Schwarzenegger (search), a Republican, also has publicly supported the research but hasn't announced a position on Proposition 71.

Shultz was secretary of state from 1982-89 under President Reagan. He is currently a fellow at the Hoover Institution (search) at Stanford University.

If voters approve the measure, the state would borrow $3 billion to fund human embryonic stem cell research and cloning projects designed solely for therapeutic purposes. Cloning to produce babies would be barred from funding.

Many scientists say stem cell research offers promise for a wide range of treatments but is being hindered by restrictive funding policies of the Bush administration.

The Roman Catholic Church, conservative Christian organizations and other moral conservatives oppose the research because days-old embryos are destroyed in the process.