In less than a decade, California has gone from being a standard-bearer for the ills of prison overcrowding to a national exemplar of reform, letting tens of thousands of people out of prison and reducing penalties for many crimes.

Important measures were passed by voters in 2014 and 2016, but only now is research starting to show the effects on crime in California. The new data is fueling a continuing debate, with national implications, about whether California should continue on the path of reform, or take a step back and get tougher, once again, on crime.

One recent study showed that an increase in crime in 2015 was not because of reforms. Another study determined that the reforms were not responsible for an increase in violent crime between 2014 and 2016 — that was from changes in reporting crime — but that they may have led to an increase in property crimes, specifically thefts from cars.

Adding to the body of evidence this week was a report on crime in 2017 released by the attorney general, Xavier Becerra. That report showed violent crime had increased 1.5 percent, while property crimes were down 2.1 percent.

The overall picture, according to supporters of criminal justice reform, is that crime is at historic lows in California. And they say that even if some categories have increased, such as thefts from automobiles, it hardly justifies a return to the days of mass incarceration.

“My main takeaway is that criminal justice reform is continuing to advance public safety,” said Lenore Anderson, the founder and executive director of Californians for Safety and Justice, which has backed reforms.

Still, it is hardly a settled matter in California. Monday, groups pushing to rollback reforms succeeded in getting enough signatures for a ballot initiative in 2020 that would reverse some of the reforms, such as expanding the types of crimes that could be charged as felonies.

This would represent a threat to one of the signature legacies of outgoing Gov. Jerry Brown, who wrote on Twitter on Monday: “Read the fine print. This flawed initiative would cost taxpayers tens of millions of dollars and endanger public safety by restricting parole and undermining inmate rehabilitation.”

The issue is a rare one that crosses party lines. While liberals tend to fall in line for reform, and Republicans are more likely to emphasize prison over rehabilitation, the lines are not clean.

One of the new ballot initiative’s top supporters is a Democrat in Sacramento — Jim Cooper, a former sheriff’s deputy turned assemblyman. And some Republicans, most prominently the former Gov. Arnold Schwarzenegger, have been voices of reform.

“This has never been a left-versus-right issue,” said Anderson, who noted that in the past, “politicians of all stripes rode the bandwagon of increased incarceration.”

This article originally appeared in The New York Times.

Tim Arango and Charles McDermid © 2018 The New York Times