A federal lawsuit filed Thursday contends the documents requirement violates the National Voter Registration Act, a federal law that aims to increase voter participation by eligible citizens.

That law is sometimes called the “Motor-Voter Law” because of a provision requiring states to provide voter registration services in conjunction with drivers’ license applications.

The ACLU lawsuit contends more than 35,000 Kansans have been blocked from voting since Kansas implemented the documentary proof-of-citizenship requirement.

One of the plaintiffs, Steven Wayne Fish, is from Lawrence. According to the lawsuit, Fish, 36, was born on a military base in Illinois that has since closed. His family moved to Kansas when he was a child. In 2014 he tried to register to vote and brought his driver’s license. After Fish completed the paperwork he was asked for proof of citizenship but did not have it. He has been unable to locate his birth certificate. The state placed him on the suspense list for voter registration.

Kansas Secretary of State Kris Kobach did not immediately return phone and email messages.

Dale Ho, the ACLU’s director of voting rights project, contends Kansas has become the nation’s “epicenter of voter suppression.”