From almost the day California's Three Strikes sentencing law was approved by voters in 1994, opponents have tried and failed to repeal or amend the politically popular measure.

Now, huge budget deficits and overcrowded prisons have given opponents of the Three Strikes Law a more attractive argument for why it should be changed: California is broke and can't afford such an expensive approach to criminal justice anymore.

By focusing on the costs of housing long-term prisoners and on the state's need to reduce its inmate population, opponents said they believe a ballot measure amending the law, promised for 2012, has its best chance of success since Three Strikes was enacted.

The dollars-and-cents argument, combined with long-standing arguments that Three Strikes is unfair, could finally be the right mix to beat back a strong lobby that over the years has included politicians fearful of being labeled "soft on crime," victims advocating for longer sentences and a wealthy prison-guard union, opponents of the law said.

A recent survey conducted by the Los Angeles Times found that 60 percent of 1,507 registered voters polled would support reducing life sentences for prisoners whose third strike was for a property crime such as auto theft or shoplifting.

"The time is right because you have fiscal considerations "... and all sorts of efforts that put strange bedfellows together for reform," said Arnold Steinberg, a Republican political strategist, at a recent forum on the topic. "There is a tremendous opportunity there."

But it's an opportunity that proponents of the law say they will vigorously fight.

"The huge savings that may be projected by the proponents of change will not bear out," said Scott Thorpe, chief executive officer of the California District Attorney's Association, a group that has always fought against a change in the law. "We think the way it has been voted in by the voters and the discretion it gives to district attorneys and the courts is the right way to do Three Strikes."

The law was approved by voters as a tonic to alleviate rising crime rates and in response to the highly publicized kidnapping and murder of 12-year-old Polly Klaas by a habitual convict wanted for parole violations. The Three Strikes Law was the embodiment of a tough-on-crime approach, handing down mandated decades-long prison terms for repeat criminals.

But the law hands discretion to county prosecutors in deciding who is eligible to be sentenced under Three Strikes, and carries a provision allowing minor crimes to trigger a third strike -- and with it a 25-years-to-life prison term that means an inmate is not eligible for parole for a quarter-century. That spawned detractors who argued that the law is inconsistently applied and unfair.

For example, a felon with two strikes who gets caught shoplifting in Bakersfield has a higher chance of getting a third strike than if that same felon was caught shoplifting in Oakland.

"The law (is) punitive without any sort of reference to whether it (is) also just," said Elizabeth Sholes, public policy director for the California Council of Churches, which supports reform. "We do know there were far too many cases where the third strike may not have been a serious or violent felony."

In fact, almost half of the more than 40,000 inmates serving time in a state prison for either a second or third strike are doing so for committing a nonviolent or nonserious crime, statistics from the California Department of Corrections show.

A study conducted by the Center on Juvenile and Criminal Justice found that the state will pay at least $10 billion over the next 25 years to house the roughly 8,000 inmates currently serving a 25-years-to-life sentence for committing a third strike.

But that estimate does not factor in the increased costs of housing aging inmates who end up needing treatment for various health problems.

"You can project ahead and see it's a huge number," said Tom Hayden, a former state senator and current director of the Peace and Justice Resource Center. "They will be in geriatric care inside the prison at unbelievable health care costs."

In addition, housing inmates with 25-to-life prison terms costs the state more because those inmates are classified as high-risk and must be placed in high-security prisons.

"It isn't overcrowding because of a lack of beds; there is also overcrowding because you don't have the right kinds of beds," said Jeannie Woodford, a former director of the state's corrections department. "You have a great portion of three-strikers who are not the typical high-level inmate but now, with the sentence, they are a Level 3 or 4."

What type of effect a reform of Three Strikes will have on the state budget, however, remains unclear, as proponents of a change have yet to detail the extent of reform they will seek from voters.

At a minimum, many said, a reform will include a provision mandating that a felon must commit a serious or violent felony to be charged with a third strike.

For the Bay Area's largest counties, such a reform will not make a big difference in how district attorneys approach a case in which a defendant is eligible to be charged with a third strike.

Statistics show that the Bay Area's three largest counties use the Three Strikes law the least. Nevertheless, proponents of Three Strikes promise to aggressively fight any reform.

"Lowering penalties is not going to decrease prison populations, it's going to increase prison populations because crime becomes more attractive," said Mike Reynolds, a vocal supporter and creator of the law whose daughter was murdered in 1992. "If you reduce penalties for crimes, you are going to see criminals committing more crimes."

Opponents of the law point to numerous studies that have shown no connection between the law and a reduction in crime and, they say, voters should reform Three Strikes because it is the morally right thing to do. With the budget crisis and prison overcrowding, those opponents believe they can convince voters of their argument.

"You can't do good stewardship without being mindful of cost -- the whole idea of being just doesn't work if in the process you are ruining your state's budget," Sholes said.