The county attorney who defended the law said he would not seek a rehearing. The only recourse for opponents appeared to be a constitutional amendment, which couldn't get on the ballot until 2012 at the earliest.
"I would say the mood is one of mourning right now in a lot of ways," said a dejected Bryan English, spokesman for the Iowa Family Policy Center, a conservative group that opposes same-sex marriage.
In the meantime, same-sex marriage opponents may try to enact residency requirements for marriage so that gays and lesbians from across the country could not travel to Iowa to wed.
U.S. Rep. Steve King, R-Iowa, urged the Legislature to do so, saying he feared without residency requirements Iowa would "become the gay marriage mecca."
Only Massachusetts and Connecticut currently permit same-sex marriage. For six months last year, California's high court allowed gay marriage before voters banned it in November.
For gays and lesbians, meanwhile, the day was one of jubilation. The Vermont House of Representatives also passed a measure Friday that would allow same-sex couples to wed, on a 94-52 roll call vote, just short of the two-thirds majority needed to override a promised veto by Gov. Jim Douglas.
Gay marriage supporters hoped to convince a few Vermont legislators to switch when it comes to the override vote, which could be taken as soon as Tuesday.
In Iowa, hundreds cheered, waved rainbow flags and shed tears of joy at rallies in seven cities Friday evening. "Corn-fed and Ready to Wed!" read one man's sign at a gathering at the University of Northern Iowa in Cedar Falls.
In downtown Des Moines, about 300 people gathered beneath rainbow flags to celebrate including Des Moines Mayor Frank Cownie.
"We finally have equality in Iowa," said Harold Delaria, of Des Moines, who attended the rally and has two gay children. "It's kind of the last wall of legalized discrimination and it's coming tumbling down."
The Rev. Diane McLanahan of Trinity United Methodist Church in Des Moines acknowledged that many people of faith won't agree with the ruling. With that in mind, she said the court has reached a decision that "pretty much insists that this will not be a debate about religious rights but a matter of equality and fairness."
In its ruling, the Supreme Court upheld an August 2007 decision by a judge who found that a state law limiting marriage to a man and a woman violates the constitutional rights of equal protection.
Iowa lawmakers have "excluded a historically disfavored class of persons from a supremely important civil institution without a constitutionally sufficient justification," the justices wrote.
To issue any other decision, the seven justices said, "would be an abdication of our constitutional duty."
At a news conference announcing the decision, plaintiff Kate Varnum, 34, introduced her partner, Trish Varnum, as "my fiance."
