Santa Monica, Calif. — Two years ago at a conference in Mexico City, Rosario Murillo, the wife of Nicaraguan junta leader Daniel Ortega Saavedra, asked a well-connected American, Blase Bonpane, to organize delegations of prominent American celebrities to Nicaragua to observe the fledgling Marxist society firsthand.
Mr. Bonpane, a former Maryknoll priest and a professor of Latin American history at the University of California at Los Angeles, is a liberation theologian sympathetic to the Sandinistas. He understood then the impact Hollywood stars could have on American public opinion.
By now American liberals have created a virtual industry of delegations to Nicaragua - a country where, not incidentally, the government is under attack by guerrillas supported by the United States. Last year, more than 2,500 Americans took part in such missions to see Nicaragua.
Delegations of church activists, college professors, architects and planners, artists and photographers, nurses and health-care workers, journalists and media professionals, Vietnam veterans, and average citizens - some activist, some just interested - have headed south.
Upon returning, many hold press conferences, frequently denouncing US support for the ''contras'' seeking to oust the Sandinista regime.
Many of the most visible critics of US policy come from Hollywood - celebrities like Ed Asner, Mike Douglas, and Susan Anspach.
Much of the Hollywood interest in Nicaragua can be traced back to Blase Bonpane, who helped organize a nine-city US tour last month with singer Jackson Browne, actors Mike Farrell and Diane Ladd, former Georgia state Sen. Julian Bond, and others. The tour was aimed at rallying opposition to US intervention in Nicaragua.
''Most of the people who have gone have not been celebrities,'' Bonpane says. But ''we do know that the United States is a media event. We have a celebrity President, and celebrities get media attention. We're aware of this now.''
Bonpane says he dislikes the notion that the Sandinista cause has become ''radical chic'' with Hollywood liberals. Those who venture to the Nicaraguan front, he says, not only are taking physical risks by entering a combat zone, but also are risking their careers by taking a public stand on a politically controversial matter.
The point of all this, Bonpane says, is not to win sympathy for the Sandinistas - although he is highly sympathetic to their cause. Rather it is to convince as many Americans as possible that there is ''no rationale whatsoever for a military solution to the problem.''
Typically, a trip organized by Bonpane and his wife, Theresa, will last a little over a week. The group will meet with government officials, labor leaders , farmworkers, and clergy, as well as visit the border region, where the contras are active. ''The purpose is to show people as much of Nicaraguan life as possible,'' Mrs. Bonpane says.
''Anybody who has a sense of claustrophobia, who feels they're being led around,'' says Mr. Bonpane, ''we don't hesitate to turn loose.'' Travelers often go to the opposition newspaper, La Prensa, or talk to cab drivers, who he says form a core of dissent.
The Bonpanes estimate they have taken 400 Americans to Nicaragua in the past two years, and they plan to launch their next delegation on Dec. 10.
Another group, the Nicaragua Exchange, based in New York City, takes a somewhat different approach. This organization sends ''brigades'' of Americans down for two- or three-week stints of harvest work on Nicaraguan plantations.
The point is both to offer some concrete aid to labor-short Nicaraguan farms and to offer Americans a glimpse of life through Nicaraguan eyes. ''It's very different to live through something than to watch it on television,'' says Sara Miles, a coordinator for the exchange.
Many of the same organizers, under a different group, sent about 650 Americans to Nicaragua in ''brigades'' last year. The Nicaragua Exchange plans to take about the same number south again this year.
The Guardian, a leftist New York weekly, has taken more than 400 people to Nicaragua since 1979, with the additional purpose of bringing the country much-needed foreign currency.
Witness for Peace, largely a religious group, has kept a continuous American presence in Nicaragua near the Honduran border as a form of nonviolent resistance to the contras and, indirectly, to the US policy that supports them.