The billions of dollars that California pours into its troubled prisons - a number fattened by court-ordered medical spending and sky-high personnel costs - have become an increasingly attractive target for leaders desperate to trim the state's $20 billion deficit.

Gov. Arnold Schwarzenegger in January called for a constitutional amendment that would cap prison spending and put the savings toward public universities. And since last summer, lawmakers have tried to wring more than $2 billion from the Department of Corrections and Rehabilitation, once budgeted for $10 billion.

But despite officials' attempts to clamp down after watching costs double over the past decade, some corrections spending is proving impervious to the budget ax.

Already, hundreds of millions in expected savings have failed to materialize, partly because one big expense - more than $1.5 billion for inmate medical care this year - is under the watch of a federal receiver, not the state.

It's also because some legislators, fearing the "soft on crime" sobriquet, balked at cost-saving measures last year that might have released thousands of the state's 160,000 inmates. That alone, the Department of Finance says, has cost nearly $600 million.

Lawmakers' dilemma

And more than two-thirds of the department's budget goes to thousands of correctional officers earning salaries locked in during California's last boom. The state must employ all those officers because of tough sentencing laws that increased the inmate population more than fivefold over the past 20 years.

The challenges only add to a portrait of crisis for California's prison system, beset by high recidivism rates and dilapidated facilities.

Paul Golaszewski of the nonpartisan Legislative Analyst's Office, which advises the Legislature on fiscal and policy issues, says reducing the number of inmates or taking a tougher stand on corrections salaries could save millions, "but they would require difficult policy decisions."

Whether lawmakers are willing to make those decisions is uncertain. While the concept of slashing prison spending is popular with voters, the outcome of those cuts - more inmates leaving custody, fewer parole agents and loosened sentencing rules - is far less so.

Lawmakers also may have to answer to the politically powerful California Correctional Peace Officers Association. The union typically has opposed measures to reduce the inmate population, since fewer inmates would require fewer officers to guard them.

Instead, some experts suggest that the state's best hope for achieving corrections cuts might come from the courts that have tied the state's hands on medical care.

Last year, U.S. District Judge Thelton Henderson - the same judge who in 2006 seized control of the prison health care system - and two other federal judges ruled that the state's 33 prisons were so inhumanely crowded that they violated inmates' constitutional rights. Some facilities are at triple their intended capacity.

The judges ordered the state to draw up a plan for releasing up to 40,000 inmates over the next two years - about a quarter of the state's prison population. With California's annual cost per inmate topping $40,000, far more than any other state, a reduction the size the judges have ordered could save billions of dollars.

Plan for reductions

The Schwarzenegger administration, backed by outraged legislators from both sides of the political aisle, has appealed that order to the U.S. Supreme Court, arguing that federal judges have no right to interfere in the state's business.

But the state also has submitted a plan for the reductions in case it loses. It would make use of private prisons, build new facilities and send some inmates to states where incarceration costs are cheaper.

Moreover, the plan would include some of the provisions the Assembly resisted last year - for example, shifting low-threat inmates into county jails. (Many local officials have decried that proposal, saying it would only push costs onto them.)

Even without those elements, California is projected to shed some 27,000 inmates by next summer. Gordon Hinkle, a spokesman for the Corrections Department, said changes the Legislature made to the state's parole system in September, minimizing technical offenses and focusing agents on high-risk parolees, will save $500 million.

Other reductions, like issuing layoff notices to several hundred prison teachers and restructuring rehabilitation programs, have been unpleasant but necessary, Hinkle said.

Health care costs

And though health care is under the domain of a court-appointed receiver, that hasn't stopped officials from trying to whittle costs. Health care over the past five years had been the fastest-growing piece of the prisons budget, more than doubling to $2 billion by 2008-09.

Lawmakers have targeted $811 million in cuts starting this summer, but the federal receiver, J. Clark Kelso, has submitted plans calling for about half that amount. He has proposed granting medical parole for terminally ill inmates, increasing use of telemedicine and establishing a central prison pharmacy - all to avoid sending inmates to outside hospitals, where corrections officers guarding them often earn overtime pay.

"This is a massive overhaul of a very large system," said Luis Patiño, Kelso's spokesman.

"It can't be done overnight, and it can't be done on a dime."