A panel made up largely of conservative delegates approved platform language that calls for a constitutional amendment banning same-sex marriage and opposes legal recognition of any sort for same-sex civil unions.
The party's full platform committee was taking up the marriage plank and other planks late Wednesday, meantime seeking ways to appease Republicans who support gay rights or abortion rights without embracing their positions.
"We are the party of the open door," said Mississippi Gov. Haley Barbour, who led platform deliberations on social issues.
But activists who support gay and abortion rights said they felt shut out, and sharply criticized their party for adopting a hard line in advance of a convention next week that will seek support from swing voters and more liberal Republicans.
Christopher Barron of Log Cabin Republicans, a GOP gay-rights group, was livid after the panel endorsed the first-ever call for a constitutional same-sex-marriage ban in a GOP platform and went beyond that to oppose legal recognition of any same-sex unions.
"You can't craft a vicious, mean-spirited platform and then try to put lipstick on the pig by putting Rudy Giuliani and Arnold Schwarzenegger on in prime time," he said in an interview.
Giuliani, former New York mayor, and California Gov. Schwarzenegger are among moderate Republicans accorded prominent convention speaking slots.
Gary Bauer, who has campaigned for the marriage amendment and against abortion rights as president of the group American Values, said the platform draft solidifies the GOP as the "party of hearth and home."
The draft urges a constitutional ban on abortion, echoing a call from previous platforms, and endorses President Bush's restrictions on federal financing of stem cell research. Some Republicans want the restrictions loosened.
Andrea Lafferty of the Traditional Values Coalition advised the network of conservative churches not to worry about the religious right's exclusion from prime time next week, given the advances against gay rights.
"Don't be distracted by Schwarzenegger or Giuliani or even the vice president," she said. "It is what George Bush says that counts and he has been faithful and fearless on this important issue."
She dismissed the other side as "RINOs" — Republicans in Name Only.
Each side claims to represent the voters Mr. Bush needs most for re-election, setting up a balancing act as the party tries to keep its religious conservatives satisfied and motivated without driving other voters away.
Bauer, for example, said Cheney's comments making clear his opposition to a constitutional ban on gay marriage were "just the sort of thing that discourages and demoralizes voters the administration desperately needs."
Ann Stone, who leads Republicans for Choice, was just as insistent. Mr. Bush must heed voters in battleground states who might be driven away by the hard line against abortion.
"Bush can't win with just his base," she said. "He needs base-plus. We are the plus."
The debate, while lively, was conducted largely in the hallways and in private meetings between party leaders and various factions.
The panel that gave initial approval to the language on family issues went through a sedate public process, with delegates reluctant to propose radical change to planks drawn up to match Mr. Bush's agenda.
But while Cheney's remarks of a day earlier prompted no discussion in the hearing, they were the subject of heavy cell-phone chatter outside the doors. Cheney, whose daughter Mary is a lesbian, said during a campaign stop Tuesday that people should be free to have the relationships they want, and existing law may well be enough to uphold traditional marriage.
Overall, Republican convention delegates overwhelmingly disapprove of same-sex marriage, according to an Associated Press survey of about three-quarters of the 2,500-plus delegates. About 72 percent said they opposed same-sex nuptials, while just over 2 percent favored it. The rest did not respond or had no opinion.
Gay-rights and abortion-rights advocates, knowing they could not shape the platform on those issues, concentrated on getting the party to adopt a "unity plank" that explicitly welcomes dissenting views on those matters. That was an uphill fight, too.
Tennessee Sen. Bill Frist, platform committee chairman, said in an interview he expected the party to make it clearer that it welcomes people who hold opposing positions. But the party was not likely to single out gay rights and abortion rights as acceptable areas of disagreement, he said.
Dealing with a document that was conservative to begin with, delegates had mixed success trying to make it even more so.
The panel toughened language endorsing sexual-abstinence education but turned aside a proposal to call for the elimination of family planning programs for teens.