LOOKING BEYOND REAGAN. GOP leaders are exhorted to widen the party's base

Republican leaders worry that their long-sought goal to become America's majority party is slipping away. A major reason: fallout from the Iran-contra affair.

The GOP's steady rise in popularity during the Reagan years has stopped. Democratic popularity among American voters once again is rising.

GOP chairman Frank Fahrenkopf, addressing a Republican leadership conference here during the past few days, urged new steps to halt the slide and regain the initiative.

Specifically, Mr. Fahrenkopf called on the GOP to broaden its appeal to a wider constituency. Republicans urgently need to win adherents among blacks, Hispanics, Roman Catholics, and labor union members, he says. Fahrenkopf believes that this can be accomplished if the GOP becomes known as ``the party of responsibility and compassion.''

The chairman charges that too often Republicans have failed to adapt to the new ethnic politics that is so important in many regions of the nation. The GOP has given the impression that ``we were closed to all except direct descendants of the Mayflower,'' he points out.

Political analysts say Fahrenkopf has reason for concern. Research by Richard Wirthlin, the President's pollster, indicates that loyalty among voters to the GOP has been declining in recent months.

In 1980, Democrats held a 50-to-25 percent lead over the GOP in voter loyalty. By November 1986, that spread had shrunk to seven points. However, Mr. Wirthlin says the margin is growing again, probably because of the Iran-contra crisis, and now is back up to a 10-percentage-point gap.

Wirthlin suggests that the first line of attack for the party must be to stop the loss of confidence in the White House. That may already have taken place, he says.

Wirthlin's polls found 52 percent of American voters disapproved of Mr. Reagan's performance before his Iran speech on March 3. After the speech, that disapproval rating dropped to 46 percent. The President's newest approval rating is 53 percent.

``Eisenhower at this point was 56 percent,'' Wirthlin observes. ``Given the shadow of Iran, that's ... not a bad base [for Reagan] from which to begin to build a stronger support level.''

Perhaps six months from now, Wirthlin believes, the President could be back into the 60 percent approval range, and rising.

Even with a stronger President, however, chairman Fahrenkopf argues that the party must do much more to keep the Reagan revolution rolling.

``We must employ our creative energies to embrace all the constituencies of America,'' he told Republicans here.

As a guide to the Republican future, Fahrenkopf cited the experiences of Gov. Thomas Kean of New Jersey.

Governor Kean was elected in 1981 by the smallest margin of victory in the state's history. Kean used his first four years in office to court blacks, unionists, and other groups, while at the same time keeping conservative Republicans happy.

In 1985, he was reelected by the largest margin in New Jersey history.

Fahrenkopf notes that Kean carried the Italian vote, the Jewish vote, the union vote, and the black vote.

``A Republican carried Newark, N.J.!'' Fahrenkopf noted with awe. ``In the process, Tom swept Republican majorities into the state assembly and a majority of the county courthouses.''

Kean did this by refusing to yield to Democrats the claim that they were the party of compassion. Fahrenkopf says, ``We must conserve and guard our principles while using our conservative philosophy in new ways to build our party and solve problems.''

He observed that the message of the 1986 elections, when the GOP lost nine United States Senate seats but picked up several governorships, was that ``the people demand quality candidates who will be practical problem-solvers, not just philosophers.''

Most important, the public wants leaders who will solve problems that are a threat to their families' well-being.

But Fahrenkopf reminds party workers that the Republican Party does not need problem-solvers who are ``hard-nosed'' with ``little concern for the people.''