Some senators and domestic-partnership advocates said Thursday's lopsided defeated of a bill to establish domestic partnerships in New Mexico was because of the New Mexico Conference of Catholic Bishops , which had been neutral on the issue in previous years, coming out against the bill this time.

Meanwhile, a lobbyist for the organization said after the vote that the bishops and supporters of Senate Bill 12 had tried to hammer out a compromise bill during the 24 hours leading up to the vote.

But the efforts fell short, said Allen Sanchez, lobbyist for the conference. A compromise bill that came out of the negotiations didn't satisfy the concerns of the bishops.

The bill by Sen. Cisco McSorley, D-Albuquerque, failed 17-25, with 10 Democrats joining all 15 Republicans in opposition.

The bill would have given unmarried couples — including same-sex couples — the ability to file as domestic partners and have many of the rights of married couples.

Opponents claimed the bill would open the door to same-sex marriage. In fact, Sen. Bill Sharer, R-Farmington, said he believes SB12 was "set up specifically to set up a court challenge," that would impose same-sex marriage rights in New Mexico.

House Republican Whip Bill Payne, R-Albuquerque, said, "If this bill would have passed, New Mexico would have been ripe for a court challenge as other states have experienced with gay marriage court rulings."

McSorley denied that was the case. Courts in two states that adopted domestic partnership laws did rule that forbidding same-sex marriage was unconstitutional. But that didn't happen in several states that have adopted such laws.

The measure had the support of Gov. Bill Richardson, who issued a statement after the vote saying, "I'm disappointed by the Senate's actions today in defeating what is fundamentally an issue of civil rights and equality."

In previous years the vote on similar bills was much closer. It failed by only one vote in the Senate in 2007.

What changed? Sanchez said court decisions in California and Connecticut determined that the domestic-partnership laws violated those states' constitutions by creating a separate-but-unequal institution.

But Sanchez noted that a court decision in Hawaii upheld that state's domestic partnership law and didn't lead to same-sex marriage.

Linda Siegle, lobbyist for Equality New Mexico, a gay and lesbian rights organization, said after the vote that the opposition of the bishops could have been a major factor in the loss of support.

Sen. Carlos Cisneros, D-Questa, agreed. He listed several Democratic senators he thought had been greatly influenced by the bishops' stance, including himself.

Cisneros on Thursday initially voted for the bill. However before the final vote was announced, Cisneros asked Lt. Gov. Diane Denish to change his vote to "no."

Afterward, Cisneros told a reporter he voted yes because he had committed to the sponsor and others to do that. But when he saw the margin was as big as it was, Cisneros said, he changed. "My preference was to vote against this bill so we could iron out some of the problems that the clergy had with it," Cisneros said.

Before the bill was debated on the Senate floor, McSorley introduced a substitute bill that took out all references to marriage and spouses from the original SB12.

But both Cisneros and Sanchez said they had a problem with a section of the compromise bill that refers to the state marriage statute.

"If they just spelled out all the rights you'd get under a domestic partnership and not refer to the marriage law, the bishops probably would drop their opposition," Sanchez said.

He said in the hours before the vote there were meetings and telephone calls involving Archbishop Michael Sheehan of the Archdiocese of Santa Fe; Bishop Ricardo Ramirez of the Diocese of Las Cruces; McSorley; House Speaker Ben Luján, D-Nambé; Rep. Mimi Stewart, D-Albuquerque, who has a similar bill in the House; and Sen. Pete Campos, D-Las Vegas.

"The bishops were trying to be compassionate," Sanchez said. "We don't want to legislate everything we believe in, but sometimes you have to stand up."

Cisneros said he could support a version of a bill like Sanchez described, with no reference to the existing marriage law. "If we could get a bill like that, I'd be glad to make a motion to reconsider," he said.

Campos, who supported domestic partnership bills in past sessions, voted against SB12. Shortly after the vote he issued a statement saying his decision to vote no was very difficult.

Campos said he was sympathetic with people who have "expressed a genuine desire to have equal rights to share personal holdings and be able to make end-of-life decisions for loved ones and lifetime partners." But the California court decision on same-sex marriage made him hesitate, he said.

"If this legislation is not enacted into law this year, I will continue to monitor the issue over the next year with the goal of preserving the institution of marriage in New Mexico while ensuring that all New Mexicans enjoy certain basic rights in their personal relationships," Campos said.

Immediately after the vote, several supporters gathered outside of the Capitol. Many were visibly shaken and shedding tears. Some speakers vowed to come back with another bill next year. "We have to tell the legislators we are not second-class citizens," said Chris Salas of Albuquerque. "We will be back every year."

Contact Steve Terrell at 986-3037 or sterrell@sfnewmexican.com. Read his political blog at roundhouseroundup.com.