Gay & Lesbian Alliance to campaign against effort to ban same-sex unions.

Emboldened by the response to Moveon.org's efforts to stir opinion against President Bush, the Gay & Lesbian Alliance Against Defamation is planning a campaign to defeat a proposed constitutional amendment that would ban same-sex marriage.

The advocacy group, based in L.A. and New York, said the effort would be the largest media blitz in its 19-year history.

In February, Bush called for an amendment "to protect marriage in America." Though little has happened since, Senate Republicans were reported to be interested in bringing the issue to a vote before August's Democratic National Convention.

If passed by Congress, the amendment would need to be ratified by three-fourths of the states. GLAAD's campaign, expected to begin some time next month, will focus on eight "swing states" the group identified as likely to play a role in the process.

"By far this is the biggest thing we have ever been involved in," said John Sonego, GLAAD's director of communications. "We see the constitutional amendment against same-sex marriage as an assault on gays.'"

In the hope of finding some memorable ads, GLAAD asked amateur filmmakers to create 30-second spots addressing the issue. The competition, which drew close to 100 entries, was modeled after a highly publicized one used by Moveon.org earlier this year.

A winner and three runner-up entries will be selected by a panel of celebrity judges and will be announced Aug. 1, with the ads expected to appear shortly thereafter.

GLAAD is spending about $300,000 to coordinate the contest and hopes to spend about $1 million to place the ads in local markets. Sonego added that the actual budget and the length of the campaign would be determined by donations generated when the winning entries are included on GLAAD's Web site.

Although $1 million is not a large media buy for television, it can make a significant difference, said Garfield Ricketts, chief executive of Round 2 Communications, a Los Angeles media-buying agency.

"They will have to be very targeted," he said. "They will have to look to venues that talk to supporters and get others to simply look at the issue and say, 'I agree that discrimination is wrong.'"

Sonego noted that entries ranged from the poignant to the absurd.

One recounted the story of an older woman who lost her house to foreclosure alter the death of her life partner. Another, titled "Straights Allowed to Marry" turns the tables on the issue to create a world where same-sex marriage is the norm.

In addition to the ads created lot the contest, two public service announcements have been recently made available by GLAAD to local television stations. One features actress Susan Sarandon and one includes "All My Children" star William Christian.

Howard Burford, the president of Prime Access, the New York ad agency that created the PSAs, noted that the objective of the GLAAD effort is to get viewers to see it as a fundamental issue of fairness.

"It is an emotional issue but an effective ad has to go beyond the heat of emotion," said Bufford.