The new rule defining “spouse” for purposes of leave under the Family and Medical Leave Act was set to take effect today. But a federal judge in Texas yesterday temporarily blocked the rule from going into effect after attorneys general in several states that do not recognize same-sex marriage challenged it.

The plaintiffs were the states of Texas, Louisiana, Arkansas, and Nebraska. They contended that the new rule violated the federal Full Faith and Credit Statute (Section 2 of the Defense of Marriage Act, which was not the part of the DOMA that was struck down by the Supreme Court in United States v. Windsor). The statute, which is still in effect, says that “No State . . . shall be required to give effect to any public act, record, or judicial proceeding of any other State . . . respecting a relationship between persons of the same sex that is treated as a marriage under the laws of such other State . . ..” By requiring the states to recognize same-sex marriages entered into in other states, the FMLA rule violated Section 2 of the DOMA, the plaintiffs said.

The plaintiffs also argued that the FMLA rule, by requiring state agencies to recognize employees’ same-sex marriages for FMLA purposes, violated those states’ own laws and constitutional provisions, which require that marriage be between one man and one woman.

Judge Reed O’Connor’s ruling in favor of the plaintiffs was temporary, not final. He ruled that the plaintiffs had shown a substantial likelihood that they would prevail and that they would be irreparably harmed if the rule were allowed to go into effect. He agreed to hold a hearing “[i]f requested by a party,” on April 13.

Assuming Judge O’Connor’s ruling does not change, the issue may become moot once the Supreme Court renders a decision in the four same-sex marriage cases it has agreed to decide this term.