Oregon is poised to step back from its first-in-the-nation drug decriminalization law with a new measure approved by the state Senate that would reinstate criminal penalties for possessing small amounts of some drugs.

The law, which took effect in 2021, decriminalized possession and personal use of all drugs, including small amounts of heroin, methamphetamine, LSD, oxycodone and others.

Supporters of revising the statute say it’s needed to address the state’s overdose crisis, while opponents say it reverts to an approach that hasn’t been beneficial and could violate civil rights.

Here’s a look at how it could change the way drug possession is handled by law enforcement and prosecutors in the state:

WHICH DRUGS WILL BE ILLEGAL TO POSSESS, AND WHICH WILL NOT?

If signed by Gov. Tina Kotek, who has indicated she is open to doing so, the measure approved Friday would restore penalties for possessing illicit drugs including cocaine, fentanyl, heroin and methamphetamine.

Possession of marijuana, which has been legalized for medical and recreational use in the state, would not be affected.

The measure also would not criminalize the controlled use of psylocibin mushrooms, which voters approved in 2020 for therapeutic use.

HOW WILL POSSESSION BE PENALIZED?

The legislation would implement jail sentences of up to six months for possessing small amounts, and police could also confiscate drugs and stop their use in parks and on sidewalks.

The measure encourages law enforcement agencies and prosecutors to refer someone arrested or cited for possession to treatment programs instead of jail. The measure also allows for people convicted of possession to have their record expunged later.

WHY DID LEGISLATORS MOVE TO CHANGE THE LAW NOW?

Oregon is experiencing one of the largest spikes in drug overdose deaths, and a 2023 audit report said the state has the second-highest rate of substance use disorder in the nation while also ranking 50th for treatment access.

That has prompted criticism and pressure by Republicans to change the decriminalization law. A well-funded ballot campaign to further weaken the statute is underway.

Researchers say it’s too soon to determine whether the decriminalization measure contributed to the increase in overdoses.

WHAT ARE CRITICS OF THE CHANGE SAYING?

Opponents of recriminalization say it reverts to a failed, decades-old approach of arresting people for possessing and using even small amounts of drugs.

They worry that it will disproportionally impact people affected by drug addiction and focuses too much on punitive measures rather than treatment. Critics have also said it will further burden public defenders’ caseloads.

“This legislation exacerbates the challenges faced by those grappling with addiction, particularly impacting Black and brown Oregonians and those experiencing homelessness,” Gloria Ochoa-Sandoval, policy director of Unite Oregon, said in a statement released by a coalition of groups opposed to the measure.