A lawsuit filed in federal court claims the constitutional amendment voters approved in 2008 barring same-sex marriage violates the equal protection and due process sections of the United States Constitution.

Attorney Shawn Aiken says there’s no legitimate basis to deny his clients the rights given to opposite-sex couples. Since two of the couples have been legally married in California , he wants the judge to mandate that Arizona recognize their marriages.

“The full faith and credit clause requires that one state recognize fill-in-the-blank: death certificate, birth certificate,” Aiken said. “Court judgments and marriage certificates fall right in the same category.”

Last year, the U.S. Supreme Court voided a section of the Defense of Marriage Act, which prevented legally performed gay marriages. That led to changes in laws, entitling legally wed gay couples to being able to file joint federal tax returns and get survivor benefits. Not addressed was a provision of the law saying states do not need to recognize same-sex marriages from other states. Aiken says federal law cannot trump the couples’ constitutional rights.