SACRAMENTO (Reuters) - California Governor Gavin Newsom on Wednesday halted the death penalty, saying he was deeply troubled by the possibility of executing an innocent person even though California voters have repeatedly backed capital punishment.

Robert Galvan, who is on death row for murder, exercises at the Adjustment Center yard during a media tour of California's Death Row at San Quentin State Prison in San Quentin, California December 29, 2015. Picture taken December 29, 2015. REUTERS/Stephen Lam

Newsom was convinced by statistics suggesting that perhaps dozens of the 737 inmates on the state’s death row were innocent. The state has not held an execution since 2006 but appeared to be moving toward resuming them.

“I couldn’t sleep at night,” Newsom said at the state capitol, adding later, “Do we have the right to kill? I don’t believe we do.”

In signing an executive order that grants reprieve to death row inmates and closes the state’s execution chamber, Newsom waded into treacherous political territory. Despite California’s liberal reputation and growing unease with the death penalty, voters have repeatedly repudiated efforts to abolish it.

As recently as 2016, a measure to abolish the death penalty failed, and another, aimed at speeding up executions, passed.

Republicans condemned the action on Wednesday, saying Newsom’s action was an offense to the families of victims of gruesome crimes.

Shawn Steele, a California representative on the Republican National Committee, said the GOP would likely use the moratorium in upcoming campaigns against Newsom and other Democrats.

“He’s putting his party in a bad spot,” Steele said.

Flanked by Democratic party leaders, Newsom said he decided to take the move because of steps by the state toward resuming executions. No death row inmates will be released under the order.

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Newsom said he had anticipated that within a month he would have been asked to sign off on a new protocol for administering lethal injections to death row inmates, clearing the way for executions to begin again.

In addition, he said, 25 of the state’s death row inmates had exhausted all of their appeals, meaning they would be in line for execution.

California’s death row is crowded with inmates, many of whom have been there for decades.

‘MORAL LEADERSHIP’

Ellen Kreitzberg, a death penalty expert and opponent at Santa Clara University law school in California, welcomed Newsom’s move.

“The moral leadership the governor is showing puts us in line with other countries and other states in terms of abolishing the death penalty,” she said.

Newsom does not have the power to overturn California’s death penalty law, Kreitzberg said, but he can refuse to sign any death warrants and can commute death sentences to life imprisonment.

On the campaign trail just last year, Newsom said he would respect the voters’ will with regard to the death penalty. But on Wednesday he said that abstract idea faded as he was personally faced with the possibility of signing death warrants.

He pointed to recent successful efforts to free inmates who were wrongly convicted, saying that roughly one in 25 felons are later found to be innocent.

With 737 inmates on death row, that equates to a possible 30 who are innocent, he said. Of the 25 who have exhausted their appeals, one could be innocent, he said.

“There could very well be a backlash,” said State Senator Nancy Skinner, a Democrat from Berkeley who supports Newsom’s move. “But I think that even people who support the death penalty don’t want us to execute an innocent person.”

California has not put an inmate to death since 2006, amid legal challenges to its execution protocols and discomfort among political leaders. But prisoners convicted of murder continue to be sentenced to death in local courtrooms.