U.S. Magistrate Judge Candy Dale ruled on Tuesday that Idaho's prohibition on marriage for gay and lesbian couples relegated them to second-class status in violation of constitutional rights to equal protection under the law.
The decision was to go into effect Friday morning but was temporarily blocked on Thursday by a U.S. appeals court as it considers the state's emergency motions for a longer stay.
Ty Carson, 41, and her lesbian partner of 15 years flew their daughter from Seattle to Boise to attend what the couple had hoped would be their wedding on Friday.
"It's a little unfortunate we have to wait a little bit longer, but we're still hopeful and excited," she said in a telephone interview.
The rally drew more than 200 people to the Ada County Courthouse, where clerks had anticipated issuing marriage licenses to same-sex couples for the first time in Idaho history, said county spokeswoman Jessica Donald.
Bolstering an atmosphere she described as festive, Barbara Fairchild, 55, of Boise, held flowers and a miniature replica of an American flag along with a sign "Equality for all." Fairchild said she is not gay but supports their right to marry.
Meanwhile, a handful of counter-protesters attended the gathering to register their opposition to gay marriage.
Retired nurse Sue Barclay, 51, said she felt the voice of Idaho's majority - who approved a constitutional amendment defining marriage as between a man and a woman in 2006 - was being silenced in court actions that have struck down bans on same-sex matrimony in nearly a dozen states.
"I support marriage between a man and a woman, and anything less will tear down the moral fabric of our country," she said.
Judy Cross, 67, countered that history was on the side of same-sex couples.
"Our right to marry in Idaho is coming and it is long overdue," she told Reuters.
The lawsuit challenging Idaho's gay marriage ban and naming the governor as a defendant was brought by four lesbian couples from Boise seeking to marry in their home state.
Republican Governor C.L. "Butch" Otter argued in legal filings that heterosexual marriage centered on the welfare of children rather than the "emotional interests of adults."