Conservatives who were searching for ways to challenge President Bush just last Christmas have all but abandoned criticism of the administration's domestic policy as the president's popularity has surged because of the Persian Gulf War.

But their reluctance to criticize Bush has not necessarily translated into wholehearted support. At their annual convention that ends here today, members of the Conservative Political Action Conference seemed more interested in dwelling on triumphs achieved during the Reagan administration.

The most warmly received speakers -- Sen. Jesse Helms (R-N.C.), activist Phyllis Schlafly and former Reagan domestic policy adviser Gary L. Bauer -- lashed out at the National Endowment for the Humanities, homosexuals and abortion rights activists lobbying for changes in the Republican Party platform.

But the several hundred conservative activists attending the conference also received mild verbal scoldings from movement leaders such as Rep. Newt Gingrich (R-Ga.) and Housing and Urban Development Secretary Jack Kemp.

"There is a fundamental problem in where we have arrived, in that there is a grave danger of the American conservative movement fighting the last war," Gingrich said. "While we have been winning the cultural war, we have been losing the political war."

Kemp who, after delivering the keynote address yesterday was challenged by questioners in the audience about his ties to organized labor, stressed that conservatives should spend as much time supporting causes as denouncing them.

"I don't blame the left; I blame the right" for not electing more conservatives to office, Kemp said. "If your product is not selling, you don't blame the consumer. You blame the merchandiser and the producer."

David Keene, chairman of the American Conservative Union, said Reagan's election was the "greatest victory of the conservative movement" and conceded that conservatives have not always been as happy with Bush, whose name was virtually unmentioned by speakers at the conference.

But the onset of the Persian Gulf War has "overshadowed" much of the criticism of Bush's handling of domestic issues such as taxes and conservative dismay over his handling of the Soviet Union's treatment of the Baltic states.

"These months have been a kind of verification of the central conservative hypotheses of the last few years," former U.N. ambassador Jeane J. Kirkpatrick said during her speech. Kirkpatrick also said the early weapons success in the Persian Gulf would build future support for the Strategic Defense Initiative.

Gingrich, one of the Bush administration's harshest critics after the president abandoned his vow to hold the line on taxes, has retreated from that stand. He said conservatives do a "huge disservice to America when we spend 60 to 80 percent of our time beating up on the president."

Keene said it is unlikely that previously disgruntled conservatives will mount a 1992 Republican challenge to the president.

There is some debate among conservatives, however, about the best way to win a quick victory in the Persian Gulf. Young Americans for Freedom President Jeffrey Wright, who co-sponsored this week's conference, called for use of nuclear weapons to avoid a ground war and "save American lives."

Keene, however, dismissed the suggestion as "politically disastrous and . . ..militarily unnecessary."

The war has given the conservatives a rallying point. "We are winning the war in the Middle East today because of the work we did in the 1980s," said Sen. Phil Gramm (Tex.), chairman of the National Republican Senatorial Committee.

Doyce A. Boesch, the committee's executive director, said the conservatives' historical support for strong defense policy has given them a political edge heading into the 1992 elections.

"That's the best political thing we've got going for us right now," he said.

Donald J. Devine, director of the Office of Personnel Management during the Reagan administration who is scheduled to speak today on a panel about conservatives and the Bush White House, said he was surprised at how much support the president was receiving at the conference.

"It looks like Bush has kind of put off any conservative challenge," Devine said.