Topeka ? A lawsuit filed Wednesday in federal court in Kansas City, Kan., seeks to overturn a state law requiring voters to show proof of U.S. citizenship to register to vote, and to block a new rule giving would-be voters only 90 days to complete their registrations.

The case was filed by former Lawrence Rep. Paul Davis, an attorney, and Will Lawrence, an attorney in Davis’ firm and a former aide to Kansas Senate Democratic Leader Anthony Hensley of Topeka. It lists two Douglas County residents as plaintiffs, Alder Cromwell and Cody Keener, both of whom have had their registrations placed “in suspense” for failure to produce proof of citizenship.

“Voting is a fundamental right guaranteed by the United States Constitution and it is imperative that this right be protected,” Davis said in a news release announcing the lawsuit.

But Kobach’s spokesman, Craig McCullah, said the lawsuit is politically motivated.

“It is interesting that the plaintiffs in this case are represented by Paul Davis — a former Democratic candidate for governor — and Will Lawrence, a former employee of (Kansas) Senate Minority Leader Anthony Hensley,” he said. “One would think these individuals would have a better understanding of the law.”

According to the complaint, Cromwell, 18, who is the son of former Lawrence City Commissioner Aron Cromwell, tried to register in March using the Kansas registration form, which also requires applicants to attest, under penalty of perjury, that they are U.S. citizens. But he did not provide separate documentation proving his citizenship, as required under the Kansas law.

“Equal representation of all people is essential in a democratic society,” Alder Cromwell said. “(Kobach is) trying to take people’s ability to vote and be represented in government. To shorten the time allowed to register to vote, you are essentially cropping out a portion of the population.”

Aron Cromwell said his son is a student at Oregon State University who decided to get involved in the lawsuit when he learned that his application would soon be purged from the list of voters whose registrations are in suspense.

“We needed somebody to stand in front and stand up for this,” Aron Cromwell said. “I got in touch with him and he said, ‘Heck yeah, I’ll do it.'”

Keener, a student at Baker University in Baldwin City, was not immediately available for comment Wednesday.

In 2011, Kansas lawmakers passed a bill, at Kobach’s urging, requiring voters to show photo ID at the polls in order to vote and requiring them to show proof of U.S. citizenship in order to register. The proof of citizenship requirement took effect in 2013.

Since then, more than 30,000 people have had their registrations placed “in suspense” for failing to show proof of citizenship. Most of those have been unable to vote, although a handful have been allowed to vote only in federal elections because they registered using a federal form, which does not require citizenship documents.

Last year, shortly before the November elections, the Journal-World analyzed the 23,774 voters who were on the suspense list at that time and found that the law had a disproportionate impact on young voters, voters with no party affiliation and voters who lived in lower-income neighborhoods.

Earlier this month, Kobach enacted a new administrative regulation that would require county election officers to cancel those incomplete applications after 90 days if the voters do not provide the necessary documents. That regulation is scheduled to take effect next month.

The lawsuit argues that the proof of citizenship rule violates the 14th Amendment to the U.S. Constitution, which says states cannot deprive citizens of certain rights without due process of law. It also alleges that the law violates the National Voter Registration Act, also known as the “motor voter” law, which requires states to accept the federal voter registration form.

The federal lawsuit filed Wednesday is just the latest in a string of legal actions that have challenged all or part of the citizenship rule.

In 2013, the U.S. Supreme Court ruled in a case from Arizona that states had to accept the federal voter registration form, but that they also could request that the U.S. Election Assistance Commission amend the form to incorporate state laws such as proof of citizenship requirements.

Both Kansas and Arizona made that request, but were turned down by the commission. The Supreme Court later rejected their request to order the commission to amend the federal form.

During the 2014 elections, while that case was pending, Kobach implemented a “dual” election system that allowed people who had registered using the federal form to vote only in federal elections. A lawsuit challenging that dual election system is still pending in Shawnee County District Court.