Washington ? Short on votes and beset by internal divisions, Senate Republicans struggled Tuesday to salvage a respectable defeat for a constitutional amendment banning gay marriage, an issue that President Bush pushed toward the top of the election-year agenda.

“This issue is not going away,” Majority Leader Bill Frist of Tennessee said in a virtual concession that the measure, co-sponsored by Kansas Sen. Sam Brownback, would fall short of the 60 votes needed to advance past today’s test vote. “Will it be back? Absolutely, yes,” he added.

Democrats, many of whom oppose the measure, took delight in the internal Republican woes, and Sen. Dick Durbin of Illinois read aloud from a recent statement on the issue by Lynne Cheney, wife of the vice president. “When it comes to conferring legal status on relationships, that is a matter that should be left to the states,” he quoted her as saying.

The emotionally charged proposal, backed by the president and many conservatives, provides that marriage within the United States “shall consist only of a man and a woman.”

A second sentence says that neither the federal nor any state constitution “shall be construed to require that marriage or the legal incidents thereof be conferred upon any union other than the union of a man and a woman.” Some critics argue that the effect of that provision would be to ban civil unions, and its inclusion in the amendment has complicated efforts by GOP leaders to gain support from wavering Republicans.

While there was no disagreement that the measure would fall short of the 60 votes needed to advance, Republicans held out hope they could gain a majority. Even that seemed in doubt, although their chances improved when an aide to Sen. John Kerry said he and vice presidential running mate John Edwards did not intend to return to the Capitol for what amounted to a procedural vote. Both men oppose the amendment.

The Senate moved toward a showdown as House Republicans pursued a different plan — seeking to pass legislation rather than an amendment.

The House Judiciary Committee scheduled a meeting today on a measure to strip federal courts of jurisdiction over a portion of a 1996 federal law that defined marriage as the union between a man and a woman.

In a string of speeches during the day, Republicans said their motivation was the defense of marriage, the well-being of children and a desire to prevent unelected judges from amending the constitution from the bench.

In a strongly worded speech, Sen. Rick Santorum, R-Pa., said some criticism ran along these lines: “Marriage is hate. Marriage is a stain. Marriage is an evil thing. That’s what we hear. People who stand for traditional marriage are haters, they’re bashers, they’re mean-spirited, they’re intolerant. … Well, we’re not,” he added.