IN MANY ways, last night's state dinner for Do- minican Republic President Salvador Jorge Blanco was a classic--a newsreel of scenes, stars and sub- stance.

First, the Brooke Watch. It was Brooke Shields' first visit to the White House, and, incidentally, in the first year she can vote for president. Photographers came from as far away as Norfolk to get pictures of the 18-year-old Princeton freshman. Twelve minutes before the dinner she arrived. Reporters screamed out questions about Michael Jackson. She shrugged and giggled and said, "I don't know."

"Who are you going to vote for?" yelled out one reporter.

"Uh. I'm not sure at the moment," she said, fidgeting from foot to foot. "I'm still learning so much about it."

Then she had an after thought. "Definitely, Reagan," she said, still shifting from foot to foot. "I'm definitely going to vote for Reagan. I haven't registered yet. But I'm going to vote for Reagan."

"Are you going to register as a Democrat or Republican?" yelled another reporter.

This one confused her. "Um, I'm not sure, I think Democrat." She quickly amended it to "Republican." That was the last question.

Then the Political Watch. On Capitol Hill yesterday, debate centered around the CIA role in mining Nicaraguan harbors and the administration's decision to refuse to accept World Court jurisdiction over its Central American policies for the next two years. In the end, the Senate voted 84 to 12 to condemn U.S. participation in the harbor mining.

Reagan, shortly after the dinner, said of the resolution sponsored by Sen. Edward M. Kennedy (D-Mass.): "If it is not binding, I can live with it. I think there is a great hysteria raised about this whole thing. We are not going to war."

"Well, the Senate vote tonight indicates the mood on the Hill," said Sen. Howell Heflin (D-Ala.). "I don't think the United States should be involved in this type of covert action." Rep. J. Kenneth Robinson (R-Va.), who is stepping down after this term, commented: "Being on the intelligence committee, that is something I don't talk about."

In the conversation with reporters, Reagan also discussed the threats of death and injury voters in El Salvador faced in their recent election. The president then noted, "They voted in higher percentages than ours. Maybe we should threaten our voters."

Asked if former president Richard Nixon had given him any pointers during their Monday night meeting marking the 35th anniversary of the Chowder and Marching Club, Reagan said they talked only during the reception, since "I didn't stay for dinner. But I have sought his counsel, as well as the other presidents, on various issues."

And then there was the Wayne Watch. When Wayne Newton--last night's after-dinner entertainment--arrived, he was holding hands with actress Marla Heasley, who blushed like a California inge'nue.

"Is that your daughter?" shouted a reporter. Newton, replendent in a black tuxedo with a red flower in his lapel, looked slightly shocked but recovered quickly. "No. My daughter is younger than this," said Newton.

Newton said it was his first visit to the White House since last year's Fourth of July celebration when he performed on the Mall. Former interior secretary James Watt put Newton in the center of controversy then when he tried to ban rock music--in this case, the Beach Boys--because it attracted the "wrong element."

Last night, Newton, who makes an estimated $12 million a year as a Las Vegas performer, said he and the First Family hadn't plotted his after-dinner entertainment. "We left that up to me. But I had a private meeting with the president today," Newton said, adding that the two discussed "just tonight."

The elegant dinner for Jorge Blanco marked the first state visit from the Dominican Republic in its 140-year history. The full protocol and schedule of the visits indicates the administration is anxious to solidify the support of the Caribbean's largest democracy and a key player in the Caribbean Basin Initiative. The republic is also a neighbor of Cuba.

In his remarks, President Reagan saluted the Dominican Republic's "creative and robust people" and its freedom. "You're meeting the challenge head on, working diligently to rebuild your economy through fiscal responsibility and courageous reform in public administration. You've improved your country's business and investment climate.

"And by stressing the importance of the private sector, and by providing practical incentives for investment you've made certain the Dominican Republic will be part of the economic upsurge now taking place in the United States as it spreads throughout the global economy," said Reagan.

Jorge Blanco, who delivered his remarks in Spanish, endorsed Reagan's Caribbean Basin Initiative but also appeared to plea for increased financial aid. "I sincerely hope that our talks will lead to appropriate and fair solutions to common problems," he said, "and will guarantee positive achievements for the development of our economies and the prosperity of our nations."

The guest list ranged from haute couture designer Oscar de la Renta to James Bond producer Albert Broccoli to artist James Wyeth to U.N. Ambassador Jeane Kirkpatrick to actress Nanette Fabray. The guests were served shrimp mousse, filet of beef in pepper sauce, a watercress and radicchio salad and pineapple en surprise.

Nancy Reagan wore a navy and white Bill Blass gown and Shields came in a black two-piece dress beaded in jet that her mother said was bought "off the rack" in Brooklyn.

And, as usual, the talk was mostly about politics. Charles Camalier Jr., chairman of the Washington store Camalier & Buckley, said his support of the Republicans would certainly continue this year. "I think everyone will do the best they can."

Jim Lake, director of communications for the Reagan-Bush Committee, was noncommital on who the Democratic opponent should be. "Whoever they nominate," he said.

Protested Maria Cole, widow of singer Nat King Cole, "Let's not make this a political evening. I have known the Reagans for years."

Fabray, who is appearing at the Hayloft Dinner Theatre, was asked how long she had known Reagan. "From when he was a Democrat," she quipped.

Logistics provided a new wrinkle for the dinner. In a vigorious spring cleaning expected to take three or four months, the National Park Service is taking at least 32 coats of paint off the front portico of the White House. While the scraping and repainting is taking place, the official party at state dinners now will arrive at the diplomatic entrance. Guests, who usually use the diplomatic entrance, are now arriving at the East Gate. Last night was the first test for this new arrangement and everything seemed to be going smoothly.

Newton's performance at the end of the evening was best described as black-tie eclectic. He played bluegrass on a white fiddle, serenaded the guests with Spanish music on his guitar, threw in a little Las Vegas with "Lady" and closed with "The Impossible Dream."

But it was still Brooke Shields' show. Guests lined up for autographs and military aides for dances. She tried to accommodate them all.

Secretary of State George Shultz got the first dance though. All eyes watched the couple. "Terrific," he later said of her dancing.

And the band played "Shall We Dance?" and everybody did. Guests at last night's state dinner:

President Salvador Jorge Blanco and Asela Mera de Jorge Blanco

Jose' Augusto Vega Imbert, minister of foreign affairs, and Mrs. Vega Imbert

Hatuey de Camps Jime nez, minister of the presidency, and Mrs. de Camps

Lt. Gen. Ramiro Matos Gonza'lez, minister of defense

Carlos Despradel, ambassador of the Dominican Republic, and Julie Catrain de Despradel

Bernardo Vega, governor of the Central Bank

Jose Michelen, executive director of the Price Stabilization Institute Carlos Morales, executive council of the National Sugar Institute

Leonel Almonte, budget counselor to President Jorge Blanco

Jose Miguel Bonetti, monetary board

Mr. and Mrs. Robert H. Adams Jr., Valley Center, Calif.

Joseph L. Allbritton, Riggs National Corp., and Barbara Allbritton

Robert Anderson, U.S. ambassador to the Dominican Republic, and Elena Anderson

Robert O. Anderson, Atlantic Richfield Co., and Barbara Anderson

Arthur I. and Martha Appleton, Surfside, Fla.

Juan Jose Arteaga, Banco Popular Dominicano, and Maria Arteaga

Rep. Les Aspin (D-Wis.) and Karen Sughrue

David and Diania Berkley, Sacramento, Calif.

Helen Boehm, Boehm Inc.

Michael M. and Doris Boich, Phoenix

Albert R. Broccoli, movie producer, and Dana Broccoli

The Vice President and Barbara Bush

Charles A. Camalier Jr., Camalier & Buckley, and Anne Camalier

James and Annie Click, Tucson

Maria Cole

Ben C. Collier, National Industries Inc., and June Collier

Martin S. Davis, Gulf & Western Industries Inc., and Luella Davis

Michael K. Deaver, deputy chief of staff and assistant to the president, and Carolyn Deaver

Oscar de la Renta

Cortlandt S. Dietler, Comar Oil Co., and Martha Sue Dietler

Gabriel Echavarria, New York, and Pilar Crespi

Ron Ely, actor, and Valerie Ely

Edward W. Estlow, E.W. Scripps Co., and Charlotte Scripps

Donald R. Fortier, deputy assistant to the president for national security affairs, and Alison Fortier

Nanette Fabray and the Right Rev. Msgr. John P. Hourihan

Sen. Howell Heflin (D-Ala.) and Elizabeth Ann Heflin

Sen. Jesse Helms (R-N.C.) and Dorothy Helms

R. Miller Hicks, R. Miller Hicks and Co., and Elizabeth Hicks

Edwin K. Hoffman, Woodward and Lothrop

Jeane Kirkpatrick, U.S. representative to the United Nations, and Evron Kirkpatrick

Barney and Diane Klinger, Santa Barbara, Calif.

Jim Lake, Reagan-Bush Committee, and Bobbie Lake

Tommy Lasorda, Los Angeles Dodgers, and Joan Lasorda

Paul Manafort, Black, Manafort and Stone, and Kathy Manafort

Edwin Meese III, counselor to the president, and Ursula Meese

Langhorne A. Motley, assistant secretary of state for Inter-American affairs, and Judy Motley

Rep. John T. Myers (R-Ind.) and Carol Myers

Wayne Newton and Marla Heasley

William B. O'Connell, U.S. League of Savings Institutions, and Marion O'Connell

Henrietta Reynolds, widow of Frank Reynolds

James E. Ritchie, James E. Ritchie Associates, and Patricia Ritchie

Rep. J. Kenneth Robinson (R-Va.) and Kit Robinson

Riordan Roett, Johns Hopkins University

Selwa W. Roosevelt, chief of protocol, and Archibald B. Roosevelt Jr.

Donald H. Rumsfeld, president's special representative for the Middle East, and Joyce Rumsfeld

Brooke Shields

Teri Shields

George P. Shultz, secretary of state, and Helena Shultz

Sen. Alan K. Simpson (R-Wyo.) and Ann Simpson

Marion H. and Frances Smoak

Norman and Erlenne Sprague, Los Angeles

Don Carlos and Pris Stansberry, Huntsville, Tenn.

George C. Stevens Jr., American Film Institute, and Elizabeth Stevens

John F. Sytsma, Brotherhood of Locomotive Engineers, and Phyllis Sytsma

William E. Timmons, Timmons and Co. Inc., and Mimi Timmons

Juan B. and Alma Vicini, Santo Domingo

Don and Dorothy Vennerson, Sugar Land, Tex.

James B. and Phyllis Wyeth

Thomas Wyman, CBS president, and Elizabeth Wyman.