Conservative activists are currently gathering signatures for an Oregon ballot initiative that would require every voter in the state to provide proof of citizenship within two years.

Initiative Petition 5, which has been approved for signature-gathering and could appear on the November 2018 ballot, would significantly increase the requirements to vote in Oregon.

All Oregonians would need to re-register by providing state officials with a birth certificate, passport or other proof of citizenship by 2020. Currently, voters need only attest to their citizenship to be allowed to vote. (Many people do present birth certificates or passports to obtain driver's licenses, the document typically used for Oregon voter registration.)

If backers gather 117,578 valid signatures, the ballot initiative could plunge Oregon into the center of national voter-suppression efforts that use unsubstantiated allegations of voter fraud as a pretext.

On Jan. 27, President Donald J. Trump took to Twitter with his claim that as many as 3 million votes in last November's election were cast illegally, many of them by non-citizens. "We must do better!" Trump tweeted. His staff and political allies have repeated such claims widely, although the evidence they present is thin.

Ari Berman, author of "Give Us The Ballot," a 2015 book chronicling the 1965 Voting Rights Act, says the Oregon initiative is part of nationwide effort that has the effect of discouraging Latinos, young voters and poor people from voting. "There is a climate of hostility toward Latinos and others from people who seem to believe all these noncitizens are registered," Berman says. "There's just no evidence of that."

Oregon might seem removed from the risk of voter disenfranchisement. The state was the first to allow its citizens to vote by mail. And in recent years, Gov. Kate Brown, a Democrat, has led the charge to make registering to vote here easier than anywhere else in the nation. The "motor voter" law she sponsored and signed in 2015 added 283,000 registered voters to the rolls last year.

But conservative activists aim to reverse those gains—with the ballot.

On Jan. 17, just 10 days before Trump's tweet, the Oregon secretary of state's Elections Division cleared IP 5 for supporters to begin gathering signatures.

James Buchal, a Portland lawyer, is one of two chief petitioners for the initiative; the other is state Rep. Mike Nearman (R-Independence).

Buchal says the measure is aimed at addressing what he calls the "low quality" of Oregon's voter rolls. He says he believes the rolls include people who are dead, residents of other states and, most problematically, non-citizens. (Federal law allows only U.S. citizens to vote.) He cannot, however, point to documented evidence of fraud here.

"There's a variety of evidence on the subject that is not specific to Oregon," says Buchal, a Republican who ran for Oregon attorney general in 2012 and for Congress in 2014. "One can make inferences from other states that there is enough non-citizen voting to make a difference in close races."

The examples Buchal cites include two small studies from Virginia and a smattering of anecdotal evidence from other jurisdictions. But the U.S. Department of Justice and groups such as the Brennan Center for Justice at New York University have repeatedly said there is no evidence of significant voter fraud in this country.

Two groups raised legal objections to IP 5 during the qualifying process late last year: Causa Oregon, a Latino rights group, and the American Civil Liberties Union of Oregon.

Andrea Miller, Causa's executive director, says the initiative would be a giant step in the wrong direction for Oregon.

Miller says IP 5 is a voter-suppression effort because it relies on documentation, such as birth certificates and passports, that many voters don't readily have on hand and that can be time-consuming and expensive to obtain. Miller says forcing everyone to re-register within two years could have a chilling effect on voters who are poor, old, unfamiliar with the law, or related to people who are undocumented.

"This wouldn't just affect Causa's constituents," Miller says. "It would impact every single voter in Oregon."

Jann Carson of the ACLU of Oregon says proponents of the measure appear to be emboldened by Trump's rhetoric.

Two years ago, Buchal and his allies proposed a similar measure that would have given voters 10 years to come up with proof of citizenship. Nobody has presented compelling evidence of voter fraud since then, but Trump has brought fringe theories into the mainstream.

"We think this initiative is a solution in search of a problem," Carson says.

Trump lost Oregon to Democratic Party nominee Hillary Clinton by 50 percent to 39 percent. But Carson says it would be a mistake to assume a voter-disenfranchisement campaign would fail here just because Oregon is a reliably blue state.

In 2004, Oregon voters approved a constitutional ban on gay marriage (later overturned by the courts) and, in 2014, rejected by a 2-to-1 margin a ballot measure that would have allowed undocumented immigrants to get driver's licenses, even though many other states allow the practice.

Carson says voter complacency in the past has led to election results that were at odds with "Oregon values" and the state's Democratic registration advantage, such as when the Oregon Citizens Alliance placed anti-gay measures on the ballot starting in 1988.

"People said, 'Don't worry, Oregonians will never pass this,'" Carson says. "That launched a series of attacks on gay and lesbian Oregonians, and it worked."