Washington ? Gay-rights advocates, outraged at what they see as the Bush administration’s decision to provoke a culture war about gay marriage, are directing much of their anger at Cheney.

Not Vice President Dick Cheney. Their target is his daughter Mary.

Ferociously loyal to her father and a senior official in the Bush-Cheney re-election campaign, the largely low-profile and openly gay Mary Cheney has been catapulted into what promises to be the most visible, contentious cultural debate of the 2004 presidential campaign.

Her father, who earlier opposed a constitutional ban on gay marriage, has backed President Bush’s recent call for such an amendment. Now Mary Cheney is under pressure from the gay community to break with her dad, resign from the campaign position that pays her a six-figure salary and denounce the Republican ticket’s treatment of gays.

“She is an ‘out’ lesbian running the re-election campaign of this ticket that is politically the most anti-gay administration of our lives,” said John Aravosis, co-founder of a Web site, DearMary.com, dedicated to lobbying Mary Cheney on the issue of gay marriage.

Since Feb. 24, when Bush announced his support for a constitutional ban on gay marriage, about 20,000 gay men and women have posted letters on DearMary.com cajoling, imploring and demanding that Cheney speak out against what they see as the administration’s treatment of gays as second-class citizens.

“Mary, you are the hopes of millions of Americans just like yourself,” wrote one correspondent, Gary of North Carolina. “Don’t miss this chance to be a hero in the eyes of your gay and lesbian brothers and sisters fighting for justice.”

Advocates plan to deliver letters from the Web site to Mary Cheney as part of a broader campaign against the proposed marriage amendment that includes organizing anti-amendment groups and running advertisements in politically crucial states.

Mary Cheney, through a campaign spokesman, declined to be interviewed.

The Rev. Joseph Lowery poses with a line drawing of Martin Luther King Jr. in Lowery's office at the Georgia Coalition for the Peoples' Agenda. A contemporary of King's, Lowery agrees that American blacks should clearly sympathize with the gay community's fight for rights.