For many, the lead villain in the rash of smash-and-grab thefts plaguing California is a sentencing reduction ballot measure that voters approved overwhelmingly seven years ago.

“I think it was the biggest con job in California history,” says Sacramento County Dist. Atty. Anne Marie Schubert, a former Republican who intends to run for state attorney general next year as an independent.

“Criminals have been laughing at us.... There’s a clear belief — and very large reality — that there’s no consequences anymore to theft.... You tell everybody we’re not going to hold anybody accountable, and guess what’s going to happen?”

The measure was Proposition 47, co-written by then-San Francisco — now Los Angeles — Dist. Atty. George Gascón and strongly supported by then-Lt. Gov. Gavin Newsom, who later was elected governor. Proposition 47 was approved by a landslide vote of roughly 60% to 40%.

The measure reduced from a possible felony to a misdemeanor the possession of narcotics for personal use and certain property crimes. The narcotics piece isn’t an issue, but the sentence reduction for thefts is.

Under 47, the crimes of petty theft, receiving stolen property and writing bad checks were lowered to misdemeanors when the value was less than $950. No prison time. In some counties, maybe a short time in jail or a wrist slap.

In 2020, voters lopsidedly rejected Proposition 20, which would have tweaked 47 by lowering the felony threshold to $250 for serial thieves.

The $950 threshold is deceiving, critics say. A thief can go from store to store, grabbing $900 worth of merchandise at each, and it’s still a misdemeanor.

“If you steal $3,500 from five stores, it’s not a felony,” Schubert says.

Newsom and Gascón still passionately defend Proposition 47.

“These organized crime waves, millions of dollars of materials have been taken. That has nothing to do with Prop. 47 and $950 because it well exceeds that,” Newsom told reporters last week. “Prop. 47 has been conveniently used, from my humble perspective, as an excuse for things that don’t necessarily have to be.

“Meaning [law enforcement] can arrest. They can hold people accountable. And they should.”

Newsom emphasized: “We need arrests and we need prosecutions. We need people held to account.… Prop. 47 seems rather insignificant in relationship to what’s been happening with these organized crime units because it’s well beyond the $950 limit.”

But Proposition 47 critics contend that the measure sent a signal that stores are easy pickings for shoplifting. And that attitude blossomed into more daring smash-and-grab attacks.

In his news conference, Newsom asserted that after 47 passed, “shoplifting dropped significantly. Property crimes dropped significantly.”

But critics counter that’s because these crimes stopped being reported.

“We have seen rampant thefts across California,” Schubert told me. “Those who say thefts are down have no concept of reality. You can walk into any grocery store and spend a half-hour and watch it happen.

“People are not reporting anymore because they know nothing will happen. Nothing. The effort it takes to report something when there are no consequences, it’s too much effort.”

Assemblyman Jim Cooper of Elk Grove, a retired Sacramento County sheriff’s captain, disagrees with fellow Democrat Newsom.

“The governor is wrong,” Cooper told me. “Shoplifting has been decriminalized, so it’s underreported. They’re not going to file a report. Police don’t respond.”

“There’s a direct correlation between rampant serial theft and voters being duped by proponents of Proposition 47,” Cooper asserted in a statement last month after flash mobs hit high-end stores. “We are watching an epidemic of theft caused by Proposition 47 that over promised and under delivered.”

Schubert contends voters were “conned” into believing that reduced sentences would save hundreds of millions of dollars — most of it to be used for mental health and drug treatment programs.

“We’re not getting people into treatment,” she says.

But that’s disputed in a study released last December by 47’s main sponsor, Californians for Safety and Justice. It reported that $200 million was being spent on mental health, substance abuse, diversion and housing programs for people charged or convicted of crimes.

Will Matthews, the group’s public affairs manager, sent me an email denouncing “baseless potshots at Prop. 47.”

He noted that several politically conservative states such as Mississippi and Texas have higher felony thresholds than liberal California’s $950.

“Meaning, it’s easier to charge shoplifting as a felony in California than in all those states,” he wrote.

Yes, but is it always being charged — as a felony or a misdemeanor?

“If someone goes into a store and takes $30 worth of food because they’re hungry, that would not be prosecuted,” says Alex Bastian, special advisor to Gascón. “But these brazen acts that are organized — someone who conspires a mass smash-and-grab — there has to be accountability.”

Bastian doesn’t think 47 needs to be altered. “We have many tools in place right now,” he insists.

But there needs to be a “carrot and stick” tool, says Rachel Michelin, president of the California Retailers Assn. Store thieves should be apprehended and, if warranted, offered treatment programs rather than jail time. Other states — including red states — do that. But it’s impossible under 47, she says.

Treatment could include job training and even potential hiring by a retailer.

“We’d rather hire someone than have them steal from us,” Michelin says.

“People are stealing because they know they can get away with it,” she adds. “Criminals frankly know Prop. 47 better than most of us do.”

Newsom characterizes the status quo as “unacceptable. Period. Full stop.”

Fine. Proposition 47 should be returned to the voters and exchanged for a product that works better for everyone, including merchants.