California’s voters in November will have their first opportunity in more than three decades to consider whether to scrap the death penalty and clear the largest death row in the nation’s history.

Reviving one of the state’s most contentious political issues, backers of a proposed ballot initiative to abolish the death penalty announced Thursday that they had more than enough signatures to put the explosive question on the November ballot. They gathered more than 800,000 signatures, 300,000 more than required, and only technical glitches would prevent a campaign that will reopen the debate over whether California should execute its most heinous murderers.

The SAFE California Act would replace the death penalty with life in prison without the possibility of parole. If approved, the law would convert the death sentences of the state’s 725 death row inmates to life in prison terms and eliminate the death penalty option in murder cases.

Californians historically have strongly supported the death penalty, famously ousting former Chief Justice Rose Bird and two Supreme Court colleagues in 1986 for refusing to uphold death sentences.

But at the same time, the state’s death penalty system has been marred by epic delays of 20 years or more in legal appeals. Just 13 inmates have been executed since the restoration of capital punishment in 1978, prompting even some leading death penalty supporters to question its benefits.

California has not executed an inmate in six years, the result of ongoing legal challenges to the state’s lethal injection method that are expected to extend a moratorium on the use of the death chamber for at least another year.

Death penalty opponents are pushing the measure as a way to save the state as much as $180 million annually, arguing that capital punishment has become an expensive waste of money at a time when California is slashing spending on everything from schools to public safety. A study last year, headed by a federal appeals court judge, concluded the state would save that much money because it costs so much more to house death row prisoners, conduct death penalty trials and for the lengthy appeals that follow convictions.

Jeanne Woodford, former chief of the state prison system and San Quentin warden, is leading the campaign, calling the death penalty no more than a “symbolic gesture.”

“(This) will put an end to its intolerable risk and exorbitant cost,” she said at a San Francisco news conference, joined by former Santa Clara County Superior Court Judge LaDoris Cordell, who is also heading the campaign.

California will jump into the death penalty debate at a time when capital punishment is in flux across the country. States such as Illinois, New Jersey and New Mexico have scrapped the death penalty in recent years, and many others have put executions on hold as a result of legal uncertainty over lethal injection or calls to study the issue. Sixteen states no longer carry out the death penalty.

The most recent Field Poll on the topic last year found 68 percent of California voters support the death penalty. But the same poll also found more of the state’s voters prefer murderers serve life in prison without the possibility of parole than get executed, a shift in attitude that SAFE leaders are hoping to exploit.

In addition to Woodford, who oversaw four executions as San Quentin’s warden, other key figures are raising questions about the death penalty, including former prosecutor Don Heller, who helped craft the 34-year-old law, and former Los Angeles District Attorney Gil Garcetti, who put dozens of killers on death row.

Chief Justice Tani Cantil-Sakauye, while not taking a position on the measure, recently told the Mercury News editorial board that she believes a re-evaluation of the law and its effectiveness is warranted.

The campaign raised $1.3 million for the signature gathering in 2011, getting checks cut by donors such as Hyatt Hotels magnate Nicholas Pritzker and Netflix CEO Reed Hastings, according to state finance records.

But death penalty supporters are lining up to combat the measure. They say the cost-savings projections are inaccurate and would vanish if the state resumes executions and begins to clear its death row. This is particularly true in the long run, they say, because the numbers of death sentences have slowed in recent years across the state, with juries sending just nine condemned inmates to San Quentin in 2011.

This newspaper reported last year that at least a dozen inmates have exhausted their legal appeals and would be in line for execution dates if the moratorium is lifted, an unprecedented number.

Law enforcement groups such as the district attorney association and police groups, along with criminal justice advocacy groups, are expected to campaign against the measure.

“If the death penalty is retained, it is now likely that most sentences will be carried out,” said Kent Scheidegger, legal director of the Sacramento-based Criminal Justice Legal Foundation, a leading advocacy group for the death penalty.

Gov. Jerry Brown and Attorney General Kamala Harris, who have both expressed opposition to the death penalty in their careers, have taken no position yet on the measure, according to their offices.

Howard Mintz covers legal affairs. Contact him at 408-286-0236. Follow him at Twitter.com/hmintz.