LOS ANGELES — California Governor Gavin Newsom announced on Thursday that he will commute the death sentences of all 548 inmates on the state's death row — the largest in the Western Hemisphere — declaring that he has concluded capital punishment is morally wrong.

The declaration came in a three-page letter addressed to "all Californians," issued as Mr. Newsom, a Democrat who is expected to seek his party's presidential nomination in 2028, approaches the end of his second and final four-year term as governor.

The move follows years of incremental steps against capital punishment in California. Mr. Newsom, who previously served as mayor of San Francisco and as lieutenant governor, imposed a moratorium on executions in March 2019, roughly two months after first taking office as governor. California has not put a prisoner to death since 2006, when Republican Arnold Schwarzenegger held the governorship.

Capital punishment nonetheless remains on the books in the state as a sentencing option unless repealed by voters or the legislature, and its practice could be restored by future governors.

California voters last upheld the death penalty in 2016, rejecting a referendum to abolish executions while approving a separate measure designed to reform and speed up the process.

Los Angeles County District Attorney Nathan Hochman said his office would continue to "evaluate every death penalty-eligible case with the rigor, care and restraint these decisions demand."

Under Mr. Newsom's sweeping grant of clemency, the sentences of all 548 condemned prisoners will be commuted to life in prison without eligibility for parole. California's constitution requires the state Supreme Court to review clemency granted to any offender twice convicted of a felony.

Mr. Newsom is the latest of more than a half-dozen US governors to have granted mass clemencies in their states in recent years, but his death row reprieve ranks as the largest yet, according to Laura Porter, head of the US Campaign to End the Death Penalty.

A Matter of Conscience

The governor said he was "acting on my long and deeply held conviction that individually and collectively we are stronger as a society when we reject state-sanctioned killing."

He acknowledged that death row inmates were convicted of causing "indescribable suffering," and that "many Californians feel that those who commit brutal crimes deserve to die."

"But as governor, I have concluded the state cannot morally kill them," Mr. Newsom wrote. "These offenders will die in prison, but not by our hand."

The US debate over capital punishment has intensified in recent weeks. In Tennessee, the execution of condemned killer Christa Pike failed on September 30 after she survived two attempts to inject her with lethal drugs. Witnesses heard Ms. Pike gasping, crying, whimpering and breathing loudly through much of the botched procedure. She was hospitalized afterward and returned to prison on October 10.

The death penalty faced further scrutiny after US Defense Secretary Pete Hegseth announced plans to livestream the planned firing-squad execution of Nidal Hasan, who was convicted of killing 13 people and wounding more than 30 others in a shooting at the Fort Hood military base in Texas on November 5, 2009. President Donald Trump later ruled out a livestream of the execution, but Mr. Hasan remains scheduled to be executed by firing squad on December 3.

Mr. Newsom's announcement came as executions were scheduled in three other states: one was carried out on Wednesday in Indiana, and two more were expected later in the day in Alabama and Florida.

At Odds With Public Opinion

The action now brands Mr. Newsom with a signature legacy on a highly contentious social issue as he lays the groundwork for what is expected to be a bid for the White House in two years.

Public support for capital punishment has been eroding. A Reuters/Ipsos poll conducted weeks after the bungled execution in Tennessee found that 55% of Americans support the death penalty for people convicted of the most serious crimes, down from 63% in 2017, while 31% said they opposed capital punishment altogether. In the same poll, one-third of respondents said they believed the government should attempt a second execution if a first attempt fails.

Globally, about 15 countries still actively carry out executions, according to the human rights group Amnesty International. Within the United States, the death penalty remains on the books in 27 states, although executions are concentrated in a handful of them, and more than 20 states have abolished capital punishment altogether.

California's cohort of condemned inmates accounts for more than a fourth of the nearly 2,000 prisoners on death row nationwide, according to the Death Penalty Information Center.

Mr. Newsom's stance on the death penalty contrasts sharply with that of Mr. Trump, who resumed US government executions following a 20-year gap near the end of his first White House term, putting 13 federal prisoners to death by lethal injection in his final few months in office.

Although the clemency act has no bearing on federal cases, Bill Essayli, a Trump-appointed US prosecutor in Los Angeles, decried Mr. Newsom's move as "a major blow to Californians and the families of victims murdered in horrific circumstances."

Opponents of the death penalty raise the possibility of wrongly executing an innocent person, note racial and socioeconomic disparities in the application of capital punishment, and argue there is no convincing evidence that it deters murder more effectively than life imprisonment without parole.

Supporters contend that capital punishment provides just punishment for the most serious crimes, deters would-be offenders and ensures murderers cannot kill again.

Source: Reuters, via BusinessWorld Online.