JEFFERSON CITY, Mo. — The U.S. Senate is expected to vote on a bill that, if passed, could protect same-sex marriage.

In the final hours before the vote, Missouri Secretary of State Jay Ashcroft urged Senator Roy Blunt, R-Mo., to “use whatever means possible to stop the passage” of the Respect for Marriage Act.

Blunt is one of 12 Republicans who joined Democrats in a procedural vote to advance the legislation earlier this month.

In a letter to the Senator, Ashcroft wrote that the act “Specifically runs afoul traditional principles of federalism,” and that it will “embolden an already weaponized U.S. Department of Justice.”

Ashcroft also said the federal law isn’t needed because Missouri voters have already voiced what they believe.

“Missourians have overwhelmingly approved marriage as a bond between one man and one woman. Over seventy percent of Missourians amended the Missouri Constitution stipulating that “to be valid and recognized in this state, a marriage shall exist only between a man and a woman,” Ashcroft wrote in the letter.

Ashcroft also wrote he believes the act is bad policy.

“I believe marriage is the exclusive, lifelong, conjugal union between one man and one woman, and any departure from that design hurts the indispensable goal of having every child raised in a stable home by a mother and a father,” Ashcroft wrote.

Blunt explained his decision to support the act in a statement released earlier in November.

“People who are legally married in one state have the same protections and responsibilities in any other state that are offered to and required of marriages. And, this legislation enhances the religious freedom for all Americans by protecting religious organizations from retaliation by federal agencies due to their views on marriage,” Blunt said.

Blunt will retire at the end of his term in January.