WASHINGTON (AP) — President Bush denounced a Massachusetts court ruling on gay marriages Feb. 4 as “deeply troubling,” and conservative activists said they had received a White House pledge that he will push for a constitutional amendment to ban same-sex weddings.

But Bush, in a written statement, stopped short of endorsing a constitutional amendment, a sensitive election-year issue.

“Marriage is a sacred institution between a man and a woman,” the president said. “If activist judges insist on redefining marriage by court order, the only alternative will be the constitutional process. We must do what is legally necessary to defend the sanctity of marriage.”

The president’s statement came after the Massachusetts Supreme Court, in an advisory opinion, said gays are entitled to nothing less than marriage and that civil unions will not suffice. The opinion set the stage for the nation’s first legally sanctioned same-sex weddings by the spring.

On the Democratic side, Massachusetts Sen. John Kerry, the front-runner for the party’s presidential nomination, said in a statement, “I believe and have fought for the principle that we should protect the fundamental rights of gay and lesbian couples —from inheritance to health benefits. I believe the right answer is civil unions. I oppose gay marriage and disagree with the Massachusetts Court’s decision.”

Retired Gen. Wesley Clark, another Democratic presidential candidate, said: “I leave that to the states and the courts — whether you call it a marriage or not, I leave up to the states and churches and synagogues and mosques.”

Bush’s statement was similar to his remarks in his Jan. 20 State of the Union address in which he said that if judges “insist on forcing their arbitrary will upon the people, the only alternative left to the people would be the constitutional process.”

Conservative activists and religious groups, banding together under the name the Arlington Group, gathered in Washington this week to plot strategy. Some participants said they left with a White House commitment to fight for a constitutional amendment.

“We were given direct assurances from the very top,” said Kelly Shackelford, president of the Texas-based Free Market Foundation. “There’s no doubt. It’s our understanding that the president is waiting for a day when there is not a massive news story to do it himself.”

Tony Perkins, president of the Family Research Council, a leading group of social conservatives, said, “I would not be surprised at all to see the president come out very soon calling on Congress to act.”

Grover Norquist, president of Americans for Tax Reform and a conservative who is close to the White House, said a constitutional amendment “is what you’d expect the president to do. ... They are forcing the president’s hand — if you say only an amendment can fix this, guess what, you’re going to get an amendment.”