PHOENIX — Attorneys for four Arizona groups involved with voter registration are trying to get a federal judge to kill a bid by Secretary of State Ken Bennett to require proof of citizenship from all who register to vote.

Nina Perales of the Mexican American Legal Defense and Educational Fund said the U.S. Supreme Court ruled earlier this year that Arizona cannot enforce its documentation requirement on those who use a registration form from the federal Election Assistance Commission.

Perales said  Bennett’s lawsuit “is essentially trying to make an end run around the U.S. Supreme Court decision.”

But Bennett said all he is doing is following a road map the high court provided when it ruled against Arizona in June.

He noted the justices said Arizona is free to ask the Election Assistance Commission to revamp its registration form to include a proof-of-citizenship requirement when individuals seek to vote in Arizona.

The justices said that if the EAC refuses — which is what its executive director did — Arizona is free to sue and, if necessary, bring the case back before them.

Bennett said that’s what he is trying to do.

The fight involves a 2004 voter-approved measure requiring proof of citizenship to register, and identification at the polls. Courts sided with the state on the ID requirement.

But the Supreme Court ruled in June that Congress specifically empowered the commission to design a national voter-registration form. It does not require documentation to prove citizenship, only that those registering swear, under penalty of perjury, that they are eligible to vote.

The court, however, did leave the option of petitioning the commission for a change.

When that was rejected, Bennett and Kansas Secretary of State Kris Kobach sought a court order to force the commission to alter its forms. Kansas has a similar proof-of-citizenship requirement.

Groups opposing the state effort include Chicanos por la Causa, Valle del Sol, the Southwest Voter Registration Project and Common Cause.

In her legal filings, Perales said these groups rely on having voter-registration forms at their offices and in community-based registration drives.

The Supreme Court’s ruling did not disturb the requirement that those who register using the state’s own form provide proof of citizenship.

She said that is why these groups want the option of using the federal form, saying that a proof requirement would “entail significant burdens for many citizens who lack the documentation required.”

Arizona law does allow a driver’s license issued after 1996 to be used as proof.

But Perales quoted Debra Lopez, who has been involved with Latino Vote Project, who said that those who do not have a license will be required to produce something else proving citizenship — and that would require Lopez to bring a copy machine to registration events.

Perales dismissed Bennett’s argument that the Supreme Court essentially invited Arizona to sue to force the Election Assistance Commission to change the registration form, saying the state’s request had already been rejected twice.