Defenders of traditional marriage say voters' resounding support for state measures that limit marriage to a union between a man and a woman proves that a federal marriage amendment is inevitable.
With five new Republican senators elected Tuesday, opponents of same-sex marriage maintain, an amendment to the U.S. Constitution could be introduced and conceivably passed as soon as the next congressional session.
"We are very encouraged," said Carrie Gordon Earll, spokeswoman for Focus on the Family in Colorado Springs, Colo. "Basically, what the people said [Tuesday] was: 'Don't mess with marriage.' "
But Matt Foreman, executive director of the National Gay and Lesbian Task Force in New York, said the vote was only Round One of a very long fight. "This is not going to shut down the debate in any way. The debate and the fight will go on."
The 11 states that passed constitutional amendments Tuesday joined seven others that earlier adopted measures to define marriage as an exclusively heterosexual institution.
The votes Tuesday against same-sex marriage were clear and conclusive.
In Mississippi, the amendment won 86% support; Arkansas, Georgia Kentucky and Oklahoma all polled at least 75% support for their amendments, and North Dakota came close to that figure. In Montana and Utah, at least two-thirds of voters supported the amendment; in Ohio, the figure was 62%, and in Michigan, 59%.
The vote was closest in Oregon, where 57% approved the ban. Most of the opposition in Oregon came from Multnomah County, where Portland is located, and where this year more than 3,000 gay and lesbian couples were married before a judge halted the practice.
Sean Cahill, policy institute director for the National Gay and Lesbian Task Force, said Wednesday that same-sex marriage supporters raised and spent close to $2.8 million to fight the amendment in Oregon. He said his organization dispatched 12 staff members to work against the Oregon amendment, and recruited 70 volunteers from within the state.
"It was the only state that had somewhat close to the resources that it needed to run somewhat close to a competitive race against this amendment," he said.
He said opponents of the measure spent $2.3 million in Oregon, not including expenditures from individual churches.
Cahill said the closer voting margin in Oregon was the result of "a lot of one-on-one talking to voters. It is tedious and it is intense. But this is a strategy that works."
Evan Wolfson, executive director of Freedom to Marry in New York, said Wednesday that a similar line of attack would be employed if Congress introduces a federal amendment to ban same-sex marriage.
"We will fight tooth and nail to protect the Constitution," Wolfson said. "We will speak out and we will tell people the stories of gay and lesbian families."
But Robert Knight, director of the Culture and Family Institute of Concerned Women for America in Washington, said Wednesday that foes of same-sex marriage sensed that momentum was on their side after the strong state amendment votes.
"People are already moving to enact constitutional amendments in other states -- specifically, I can think of Pennsylvania and Illinois," Knight said. "Letters have already been sent to [ Republican] Party leaders urging them to join the marriage bandwagon."
In May, Massachusetts became the only state to permit gays and lesbians to marry, after a ruling by that state's highest court. Knight predicted, however, that "same-sex marriage will not survive in Massachusetts."
If other states legalize same-sex marriage, he said, "it will be seen as a bizarre exception to the national trend. America spoke loudly and clearly on Tuesday and said, this has gone too far, and it is time to turn back toward moral normalcy."
Knight went so far as to suggest that " President Bush should send a bouquet of flowers" to the members of the Massachusetts Supreme Judicial Court who wrote the decision legalizing same-sex marriage there.
"If they had not struck down [traditional] marriage in Massachusetts, this issue would not have generated such passion among evangelical Christians, who made the difference in this presidential election," Knight said.
But some political analysts and many Internet bloggers were more inclined to lay responsibility for same-sex marriage on San Francisco Mayor Gavin Newsom, who authorized city officials to issue more than 4,000 marriage licenses to same-sex couples this year. The California Supreme Court stopped the marriages, and is expected to hear a constitutional challenge to state marriage laws within two years.
Newsom reacted defensively Wednesday, saying the "activist judges" in Massachusetts took the first step toward legalizing same-sex marriage. Asked Wednesday if same-sex marriage had coalesced the conservative vote, Sen. Dianne Feinstein (D-Calif.) said: "I think it gave them a position to rally around. The whole issue was too much, too fast, too soon."
Times staff writer Lee Romney contributed to this report.