With gays and lesbians now legally wed in Massachusetts, foes of gay marriage (search) vowed Tuesday to campaign hard, in state and national elections, for candidates willing to reverse the tide.

"It's very difficult, once a right has been claimed in law, to reverse that right, but we're going to try," said the Rev. Christopher Coyne, spokesman for the Roman Catholic Archdiocese of Boston.

The election battle will be waged on two main fronts: an effort nationally to elect congressional candidates supporting a constitutional ban on gay marriage, and an effort in Massachusetts to tilt the balance in the Legislature by ousting 10 to 20 lawmakers who opposed a state ban.

"We're not going to let this issue go away," said Kristian Mineau, president of the conservative Massachusetts Family Institute (search). "Our theme is 'Remember in November.'"

More than 1,000 same-sex couples — including scores from other states — have obtained marriage licenses since Massachusetts on Monday became the first state to allow gays to wed.

Protests were few, and sparsely attended, but Mineau said that reflected a deliberate decision by his group and others to avoid confrontations and to focus their energy against politicians, not gay couples.

"Homosexual couples are not the enemy," said Raymond Flynn, a former Boston mayor and foe of gay marriage. "The enemy is the legislators who ignored and betrayed the people of Massachusetts by not giving them an opportunity to express their point of view."

Legislators wrangled for months after the state Supreme Judicial Court, in a 4-3 decision last November, ruled that gay couples were entitled to marry. Eventually, in a compromise that dismayed activists on each side, lawmakers took the first step toward letting voters decide in 2006 if they want to amend the constitution to ban gay marriages and allow gay couples enter civil unions.

"Without a change in the makeup of the Legislature, we don't have an opportunity to get a real amendment passed," said Michael Carl, president of a political action committee called the Heritage Alliance (search) that wants both civil unions and gay marriage banned. Carl said the alliance has recruited more than 20 legislative candidates "willing to take a courageous stand."

Coyne said Catholic Church leaders, though avoiding partisan politics, would make clear to Catholic voters that gay marriage is a factor they should consider when casting their votes this fall. However, he acknowledged the task of gay-marriage opponents is now more daunting.

"Obviously the issue has become so much more complex now with the reality of same-sex marriage," he said. "When you talk about withdrawing that reality from these couples, you're just opening a whole can of worms."

Nationally, conservative leaders are working to build support for a proposed federal constitutional amendment (search) — pending in Congress — that would prohibit gay marriages nationwide.

Tony Perkins, president of the Washington-based Family Research Council (search), said the amendment is the only sure defense against the expected wave of lawsuits by same-sex couples who marry in Massachusetts, then return home to other states and seek recognition of their unions there.

"This issue is boiling," Perkins said. "It's gone from an academic debate to a real public policy crisis."

The federal amendment must first be supported by two-thirds of both the House and Senate, then be ratified by at least 38 legislatures, representing three-quarters of the states.

Richard Land, president of the Southern Baptist Convention's Ethics and Religious Liberty Commission (search), said he was concerned because several members of Congress told him recently they were getting little pressure from their constituents to push for the amendment.

Another line of attack against same-sex marriage is pending in federal court. An appeals court in Boston is scheduled to hear arguments next month from lawyers contending that the Supreme Judicial Court had no authority to issue a ruling defining marriage in Massachusetts.

Mathew Staver of the Florida-based Liberty Counsel (search), one of the conservative lawyers handling the federal case, said such legal efforts should be complemented by a stronger push from the White House on behalf of the proposed constitutional ban.

"President Bush needs to do more than make a public statement," Staver said. "He should appoint a pro-marriage advocate to his staff whose sole job is to push forward a constitutional amendment ... to educate, motivate and direct the strategy."