Evoking Ronald Reagan and Barry Goldwater, a group of Western-state Republicans plans to enter the battle in favor of same-sex marriage on Tuesday, urging a federal appeals court to declare gay marriage bans in Utah and Oklahoma unconstitutional.
The most prominent of the approximately 20 signers of the brief are former Senator Alan K. Simpson of Wyoming, a longtime supporter of gay rights, and former Senator Nancy L. Kassebaum of Kansas, who said last year that she had reconsidered her former opposition to same-sex marriage. The document says that “marriage is strengthened” and “the social stability of the family unit are promoted” by allowing gay and lesbian couples to marry.
The document is a friend-of-the-court brief, being filed to the United States Court of Appeals for the 10th Circuit, in Denver. That court is hearing appeals from Utah and Oklahoma to reinstate their restrictive marriage laws.
The brief was the latest sign of widening cracks in Republican opposition to same-sex marriage, even deep in the country’s conservative heartland.
Last month, a New York Times/CBS News poll found a rapid shift in Republican attitudes nationwide. Forty percent of Republicans said same-sex marriage should be legal, up from 33 percent last May and only 24 percent in September 2012.
Sean Gallagher, a lawyer and Republican Party activist in Denver who helped prepare the brief, said many Republicans were rethinking their positions. “The themes of liberty and freedom resonate especially well in the West,” said Mr. Gallagher, who was chief counsel in Colorado for Mitt Romney’s presidential campaign in 2012.
Early last year, dozens of Republicans, including four former governors and former White House officials, joined in a similar legal brief to the Supreme Court, arguing that gay people have a constitutional right to marry. Neither Mr. Simpson nor Ms. Kassebaum signed that document.
In December, a federal court in Utah overturned the state’s amendment restricting marriage to a man and a woman. In January, a federal court in Oklahoma struck down that state’s ban on gay marriage.
Utah and Oklahoma appealed, and the cases are on a fast track in Denver, with hearings scheduled in April.
If the appeals court upholds the current rulings, same-sex marriage could become legal throughout the judicial circuit — in Colorado, Kansas, New Mexico, Oklahoma, Utah and Wyoming — barring a counterdecision by the United States Supreme Court.
In other signs of change in the mountain West, in December the New Mexican Supreme Court ruled that gay and lesbian couples have a right to marry. Gov. Susana Martinez, a Republican, accepted the decision as “the law of the land.”
In Nevada, the state prevailed in court in 2012 in its defense of marriage restrictions. The gay and lesbian plaintiffs appealed to the Court of Appeals for the Ninth Circuit, in San Francisco, and last month Nevada’s Republican governor, Brian Sandoval, agreed to withdraw from the case, saying that defense of a same-sex marriage ban was not legally tenable.