Mr. Paterson declined a request for an interview.

The Maine referendum, in which voters reversed lawmakers’ earlier approval of same-sex marriage, was not the only cause for concern for supporters of the bill.

During the bitter fight for the 23rd Congressional District in upstate New York in recent weeks, state conservatives pressured the Republican candidate to withdraw in part because of her support of same-sex marriage. And Gov. Jon S. Corzine’s defeat in New Jersey has complicated efforts to legalize same-sex marriage there.

Opponents of the measure in New York expressed confidence that they would prevail.

“I think we’re starting from a position of strength,” said Jason J. McGuire, executive director of New Yorkers for Constitutional Freedoms. “I don’t believe they have the votes, and it’s an act of desperation. Our position is to maintain the votes we have, and people are certainly in contact with our senators and we are encouraging that. This is not going to pass.”

Republican officials said Senator Dean G. Skelos, the leader of the Republican caucus, would allow his colleagues to vote however they wanted and would not seek a unified position. But none of the 30 Republicans have yet to commit publicly to voting for same-sex marriage, and the bill’s supporters say that Republican votes are needed for the measure to pass.

Democrats were to meet in a closed-door caucus on Monday in Albany to decide how to proceed.

“There is a school of thought which says that unless you have 32 votes, you shouldn’t pull a bill on the floor,” Pedro Espada Jr., the Senate majority leader, said in an interview on Saturday. “There’s also an equally valid school of thought that says we should put it up for a vote and live with the results.”

Mr. Espada, a supporter of the measure, said he and a number of other Senate Democrats, including the caucus leader, John L. Sampson of Brooklyn, had been discussing strategy while attending a conference of Latino lawmakers in Puerto Rico this weekend.

Senator Rubén Díaz Sr., a Pentecostal minister and Bronx Democrat who is the most outspoken opponent of same-sex marriage in the Legislature, said last week that the issue should be voted on during an election year.