House Democrats on Wednesday filed an amicus brief in a Tenth Circuit court of appeals case on voter registration laws.

At issue in the case, Kris W. Kobach v. Election Assistance Commission, is whether states can require people to submit proof of citizenship with the federal voter registration form.

The prosecutors in the suit, the states of Arizona and Kansas, have argued that they should be able to require additional proof of documentation in order to register to vote. But opponents say that allowing certain states to mandate different requirements on a federal voter registration form would circumvent the authority of Congress.

In an amicus brief, Democrats including House Minority Leader Nancy PelosiNancy Patricia D'Alesandro PelosiDemocrats search for 51st net neutrality vote Hoyer suggests Dems won't support spending bill without DACA fix Trump’s first year in office was the year of the woman MORE (Calif.), House Minority Whip Steny HoyerSteny Hamilton HoyerMcCarthy: ‘No deadline on DACA’ Lawmakers see shutdown’s odds rising Hoyer suggests Dems won't support spending bill without DACA fix MORE (Md.), Assistant Minority Leader James Clyburn (S.C.)., and Rep. Robert Brady (Pa.), the ranking member on the House Administration Committee, argued that imposing additional requirements would result in voter suppression. They noted that the people already must attest to citizenship on the federal voter registration form.

"For much of our nation’s history, state law was used to diminish or deny qualified citizens the right to vote. The Constitution was amended to correct that wrong and to empower Congress to take appropriate steps to ensure that history does not repeat itself," the lawmakers wrote. 

They further pointed to a June 2013 Supreme Court opinion that invalidated Arizona's voter registration law requiring proof of citizenship. 

"Unless a state can demonstrate that it has been denied the only available means to assess an application's qualifications, no constitutional question arises," they wrote. 

Congressional Black Caucus Chairwoman Marcia Fudge (D-Ohio), Congressional Hispanic Caucus Chairman Ruben Hinojosa (D-Texas) and Congressional Asian Pacific American Caucus Chairwoman Judy Chu (D-Calif.) also signed onto the amicus brief.

The amicus brief is part of House Democrats' push against restrictive voter ID laws ahead of the midterm elections. At least eight states are expected to have photo ID requirements in November.