TOPEKA ? Kansas Secretary of State Kris Kobach has asked a federal court to set aside a default judgment against him for failing to file a timely response to a lawsuit challenging the constitutionality of a state law requiring prospective voters to prove they are U.S. citizens.

A federal court clerk earlier this week entered Kobach as being in default in a case concerning the state’s proof-of-citizenship requirement because Kobach had failed to file documents with the court on time.

In a motion filed Friday in U.S. District Court, Kobach asked the court to set aside the default judgment, saying he believed the court had suspended certain deadlines in the case. He also criticized his opponents for “trying to play a game of ‘gotcha’ litigation,” The Wichita Eagle reported.

“They keep changing their complaint and forcing us to write a new answer,” he said.

Will Lawrence, an attorney for the plaintiffs, said the original complaint was amended for legitimate reasons, including a ruling in a separate case that settled some of the matters before the court.

The lawsuit contends the proof-of-citizenship requirement violates voters’ constitutional right to due process and the right to freely travel from state to state by infringing on people’s ability to vote and to sign petitions. It also contends that the actions Kobach has taken to verify citizenship status discriminate against people who were born or got married in other states.

Kobach has championed the proof-of-citizenship requirement as an anti-fraud measure that keeps non-citizens from voting. Critics say such requirements are actually meant to suppress voter turnout among groups that tend to support Democrats and that the type of in-person voter fraud they are designed to prevent is extremely rare.

Federal Judge Julie Robinson will decide whether to set aside Kobach’s default status in the case. If she upholds the default, the plaintiffs will have succeeded in overturning the state’s proof-of-citizenship requirement.