SALEM — An attempt to repeal a new state law allowing undocumented immigrants to get Oregon driver’s licenses has hit a snag.

Oregon Secretary of State Bev Clarno on Tuesday halted a proposed ballot initiative to walk back House Bill 2015, saying it doesn’t comply with requirements stated in the Oregon Constitution.

The bill, passed earlier this year, allows Oregonians to present forms of ID that don’t prove a person’s legal immigration status in order to get a driver’s license. The licenses will not be available until Jan. 1, 2021.

Undocumented immigrants — or others without documents proving U.S. citizenship or that they are in the country legally — have been barred from getting driver’s licenses in Oregon since 2007.

Supporters of the petition want to prevent people who are here illegally from getting state driver’s licenses.

The campaign to repeal the law, which calls itself “Stop Illegal Drivers,” is led by Mark Callahan, a frequent candidate for political office in Oregon.

Callahan, reached for comment Tuesday, said the campaign was “definitely going to fight” the ruling, and pointed to several previous cases he believes support his interpretation that the petition passes muster.

The Secretary of State’s Office believes the constitution requires the petitioners to present the changes the petition would make to state statutes. Instead, the ballot title just says that a “Yes” vote on the petition “‘Demands’ repeal” of the bill.

In a post on the “Stop Illegal Drivers” website, the campaign said the reason Elections Director Steve Trout gave — the constitutional requirement cited by Clarno — was “not valid.”

The campaign also posted on the website a message from Callahan addressed to Trout. Callahan called the reason for the rejection “flawed in logic and reasoning.” He maintained the petition was not trying to pass a new law.

“How can we submit the full text of a law that we are NOT ‘Proposing?’” Callahan wrote. “It doesn’t make any sense. If we are NOT ‘Proposing’ a law, there is no full text of a law to submit.”

Oregon’s constitution includes several ways that Oregonians can have a direct say on a policy at the ballot box.

Lawmakers can refer a measure to the ballot; citizens can ask for a referendum on a particular law; or citizens can file an initiative petition to change state laws.

A referendum, which simply asks voters to reject or keep a law state legislators pass, differs from an initiative petition.

In the case of House Bill 2015, petitioners could not submit a referendum. That’s because of a few words in the bill that amount to an “emergency clause.”

That clause says the bill takes effect as soon as lawmakers pass it. The state constitution doesn’t allow bills that go into effect that soon to get referred.

But citizens can file an initiative petition in that case. That’s what the backers of Initiative Petition 43 did.

Since they filed an initiative petition, the Secretary of State’s Office says, petitioners were supposed to present an amended form of the law for voters’ consideration, showing exactly how the law would be changed if the provisions of House Bill 2015 were repealed.

But the petition they submitted just “demanded” repeal of the law.

House Bill 2015 affected many parts of state law, said Deputy Secretary of State Rich Vial.

“We feel like you need to put the sections that were originally affected by the legislation in to the petition and show what you would propose to take back out of the law or change it back to what it was before,” Vial said. “The law, obviously, was complicated enough that there was a number of things in the statute that were added or changed.”

Moving forward, the petitioners could rewrite the petition and re-gather the sponsorship signatures in order to get another ballot title drafted, at which point the Secretary of State’s Office would review both again for constitutionality, Vial said.

But in cases like this, if petitioners don’t want to rewrite the measure, sometimes they will bring a lawsuit.

Supporters of the petition argue House Bill 2015 contradicted the will of Oregon voters, who in 2014 rejected a measure to create a separate type of license for people who cannot prove they are in the country legally.

Proponents of House Bill 2015 said that bill would simply allow Oregonians to present forms of personal identification that don’t prove legal status. It would also apply to people who didn’t have access to vital records, such as people who are experiencing homelessness.

House Bill 2015 also says licenses granted to those who don’t present proof of citizenship do not meet federal “Real ID” standards.

The new IDs, a post-9/11 policy intended to strengthen security, will be required for Oregonians to enter certain federal buildings and to board commercial flights starting Oct. 1, 2020.

Members of the public had complained the ballot title was misleading. The ballot title said the effect of the “demand” stated in the petition was unclear.

Several commenters, in response, provided the dictionary definition of “demand.”

One member of the public, Kaila Calkins, wrote an email to the Secretary of State’ Office saying that “this is nothing more than another political ploy to effectively silence the Oregon voter.”

Clarno said in a statement she hoped the petitioners would “take (her) ruling as an opportunity to improve their proposal.”

“The initiative petition process is very important in giving Oregonians an opportunity to directly participate in our government,” Clarno said in a statement. “It is my sincere hope that the proponents of this ballot measure will take my ruling as an opportunity to improve their proposal. I will always support the presentation of ballot measures that meet constitutional requirements.”