Although he has served as governor longer than anyone else in California history, Jerry Brown has never been forced to make one of the weightiest decisions governors face: whether to spare a convicted criminal from execution.

California has executed more than 500 people, but the death penalty has been on hold pending legal challenges during both of Brown’s two-term stints as governor. It’s been a politically convenient coincidence for the Democrat who rose to prominence as an outspoken opponent of capital punishment, even as California voters repeatedly demonstrated support for it.

Their most recent affirmation came this November. Voters rejected Proposition 62, which would have abolished capital punishment, and passed Proposition 66, which seeks to expedite death penalty appeals. The outcome means California may resume executions during Brown’s final two years as governor, potentially challenging the legacy of the former Jesuit seminarian who was once so morally opposed to capital punishment that he protested outside the gates of death row.

It’s not certain that executions will resume; death penalty opponents have filed a lawsuit trying to block Proposition 66 and a separate challenge of a law that gives corrections officials broad authority to establish execution procedures. A federal court would need to lift a decade-old stay on lethal injections in California.

But supporters insist they will prevail in court and that executions will begin next year.

They were suspended in California in 2006 when a federal court ruled that the state’s three-drug lethal injection process amounted to cruel and unusual punishment.

Since then, corrections officials have been drafting a new execution procedure using only one drug, while also responding to a tangle of lawsuits challenging the way they were planning to reinstate the death penalty.

The single-drug plan introduced last year, like many proposed state regulations, doesn’t go into effect until after a public review period. But one piece of Proposition 66 removes that review period, allowing prison officials to more swiftly move ahead with single-drug lethal injections.

“The (corrections department) should be able to begin use of the protocol that it’s already established, which means that execution dates can be set,” said Kent Scheidegger, a Sacramento attorney who helped write Proposition 66, and whom The Atlantic once called “Mr. Death Penalty” for his advocacy on the issue.

“I’m sure it will be an intensely fought battle. But we’ll certainly make the argument that there’s been far too much delay and courts shouldn’t delay any further.”

If courts allow Proposition 66 to proceed — more action on the suit is expected after election results are certified in mid-December — execution dates would be established after district attorneys seek death warrants from the trial courts.

Eighteen of the 748 death row inmates have exhausted all their appeals, making them likely to be executed soonest. They include Harvey Heishman, who raped an Oakland woman and then murdered her in 1979 before she could testify against him; Richard Samayoa, who broke into a San Diego home in 1985 and beat a young mother and her toddler to death with a wrench; and Tiequon Cox, who murdered four Los Angeles family members of Kermit Alexander, the former pro football player who put Proposition 66 on the ballot.

Despite his activism against the death penalty as a young man, Brown never weighed in publicly on the November initiatives.

“I think he just felt he would be compelled to do whatever the voters decide and therefore did not enter into the fray,” said Cruz Reynoso, a former California Supreme Court justice and death penalty opponent.

Reynoso — one of three Brown appointees tossed off the Supreme Court in a 1986 campaign that targeted them for overturning death sentences — said if executions are scheduled before 2018, he wouldn’t expect Brown to block them. “Jerry Brown, like yours truly, may have a moral position,” he said, “but as a public official will enforce the law.”

The governor’s staff declined to answer questions about potential executions. But Brown biographer Chuck McFadden said if executions did resume in his final term, “He wouldn’t like it, not one bit.

“It’s an open question whether he would say anything publicly decrying the execution. … But he would certainly be unhappy about it, even though he’s a far different person today than he was in 1960.”

In that year, Brown famously lobbied his father, then-Gov. Pat Brown, to stay the execution of a convicted rapist. Seven years later, the younger Brown stood vigil outside of San Quentin as a cop killer was put to death inside the prison

Governors have broad authority under state law to block executions. The elder Brown spared 23 death row inmates by commuting their sentences but allowed 36 to be executed. In his biography “Public Justice, Private Mercy: A Governor’s Education on Death Row,” Pat Brown described the difficulty of being “the last stop on the road to the gas chamber.

“It was an awesome, ultimate power over the lives of others that no person or government should have, or crave,” wrote Pat Brown, who contended that his qualms about it helped Ronald Reagan unseat him in 1966.

After 1967, legal challenges put the death penalty on hold in California for 25 years. Because Jerry Brown’s first two terms as governor (from 1975-1983) came during this hiatus, he avoided the clemency decisions that had racked his father.

As a young governor, Jerry Brown took other actions reflecting his objection to capital punishment and met resistance. In 1977 he vetoed a bill to reinstate it after courts had abolished it, only to see the Legislature overrule his veto. In 1978, voters re-elected Brown even as they approved an initiative creating the death penalty law still on the books today. Brown appointed justices opposed to executions, only to see voters refuse to retain them.

By the time the state resumed executions in 1992, Brown was running for president and touting his “uncompromising” opposition to capital punishment.

“When someone is contained in a cage, then to bureaucratically, cold-bloodedly snuff out their life, whether by poison or electrocution or by gas, it doesn’t seem right to me,” Brown said that year.

In 2007 he became California’s attorney general, a position that required him to defend hundreds of death penalty convictions even as the state stopped executions due to lawsuits over lethal injection. It took nearly a decade to produce a new lethal injection plan, a slow process some blamed on Brown.

Campaigning for governor in 2010, he said he would prefer a society “where we didn’t have to use death as a punishment,” but recognized his opinion had been overruled by lawmakers and voters. He promised to carry out the death penalty “with compassion but … with great fidelity to the rule of law.”

Some of the inmates awaiting lethal injection on death row

• Henry Duncan: Stabbed his cafeteria supervisor at Los Angeles International Airport in 1974.

• Lavell Frierson: Shot two Peruvian airline employees outside an Inglewood motel in 1978.

• Lawrence Bittaker: Kidnapped five girls from South Bay streets in 1979, and tortured, raped and killed them.

• Melvin Turner: Shot a doctor and schoolteacher to death execution-style in a Torrance Municipal Airport hangar in 1979.

• Andre Alexander: Shot a U.S. Secret Service agent to death near Los Angeles International Airport in 1980.

• Jose Leon Fuentes: Robbed and killed a Brink’s security guard at a Torrance department store in 1981.

• Earl Preston Jones: Inglewood landlord shot two tenants to death during a rent dispute in 1984.

• Arthur Halvorsen: Shot four people to death after he was fired from a Wilmington trucking firm in 1985.

• Evan Nakahara: Robbed and killed his girlfriend to obtain her father’s $20,000 gun collection in San Pedro in 1989.

• Jesse Morrison: Broke into a boxer’s home in Wilmington, shot him twice in the head and stole his family’s minivan and cash in 1989.

• Lester Wayne Virgil: Stabbed a Gardena doughnut shop clerk to death in a 1992 robbery. He got $12.

• Regis Deon Thomas: San Pedro gang member killed two Compton police officers in 1993 when they pulled him over. Also convicted of killing a man in Los Angeles in 1992.

• Randy Eugene Garcia : Tied up and shot a woman in her Torrance house in 1993, attempted to rape her and killed her husband when he arrived home. The wife survived.

• Roger Hoan Brady: Shot and killed a Manhattan Beach police officer during a traffic stop in 1993.

• Maurice Harris: Robbed and killed his pregnant fiancee, then shot a man who owed him $1,500 in Gardena in 1994.

• Raymond Oscar Butler: Killed two Marymount College students in a San Pedro parking lot in 1994. Received another death sentence for killing a fellow jail inmate in 1995.

• Dewayne Carey: Stabbed a Harbor City woman to death in 1995 when she arrived home and found him burglarizing it.

• Kendrick Loot: Killed two armored car guards and another man in Long Beach and Carson in 1995 and 1996.

• Bruce Millsap: Kendrick Loot’s partner in killings of two armored car guards and six other people in 1995 and 1996. Received eight death sentences.

• Spencer Brasure: Hogtied, gagged and tortured a Redondo Beach man in a Lawndale home in 1996, then set him on fire while still alive in a Ventura County field.

• Eloy Loy: Raped and killed his 12-year-old niece and dumped her body in a field in 1996.

• David Arisman: Sexually assaulted a Manhattan Beach office worker, then shot an Office Depot deliveryman to death who walked in on the crime in 1997.

• Donald Debose Jr.: Followed a woman from Hollywood Park Casino in 1997, kidnapped, beat and raped her, and stuffed her in the trunk of her car and set it ablaze.

• William Satele: Along with Daniel Nunez, Latino gang member shot and killed a Harbor City couple as they kissed outside a home in 1998, purportedly because they were black.

• Daniel Nunez: Along with William Satele, Latino gang member shot and killed a Harbor City couple as they kissed outside a home in 1998, purportedly because they were black.

• Miguel Magallon: Killed a police officer who worked at County Harbor-UCLA Medical Center as the officer rode his bike to work through the unincorporated area north of Carson in 2004.

• Jonathan Fajardo: Latino gang member killed a 14-year-old girl because she was black in Harbor Gateway in 2006, then stabbed and killed a fellow gang member in Carson, mistakenly believing he had talked to police.

• Ricky Madison: Stabbed his mistress 172 times in Hawthorne in 2006.