The United States is heavily favored to beat South Africa in the Davis Cup American Zone semifinals starting Friday at Newport Beach, Ca!, but the tennis aspects of the series have been overshadowed by its political ramifications.

Several groups are planning demonstrations to protest the apartheid racial policies of the South African government and that nation's involvement in international sports.

An ad hoc group called the Committee to Stop the United States-South Africa Tennis Match has planned picketing of the host Newport Beach Tennis Club before and during matches on Friday, Saturday and Sunday.

Vincent Perkins told The Washington Post that the Pasadena-based group of which is a chairperson hopes that slogan-chanting picketers will force cancellation of the series, but that the committee will not attempt to physically disrupt the matches.

"Our thing is to stop it by legal and peaceful means. There will be a lot of noise, but no on-court sit-ins or illegal activities," said Perkins, whose group claims between 75 and 100 members.

Perkins said that between 1,000 and 2,000 protesters are expected to come by car pool and bus from a geographical radius of some 300 miles, including Los Angeles and San Diego.

Several African-based organizations have also warned that the match could lead to African boycotts of all international sporting events in which Americans participate.

"The Supreme Council for Sport in Africa and the Organization for African countries," said Dennis Bruto of tennis match takes place, all American athletes, black or white, in all sports will be boycotted by the Afri - countries," said Dennis Bruto suf Chicago, the black South African exile who founded and heads the South African Non-Racial Olympic Committee (SANROC).

Brutus, a professor specializing in African literature at Northwestern University, said that he has written to President Carter, United Nations Ambassador Andrew J. Young, officials of the U.S. Tennis Association and U.S. Olympic Committee, and others "in order to draw their attention to the serious problems associated with this match." He has had no formal replies, he said.

Brutus, who has been associated with numerous anti-South African protests, including the African boycotts of the 1968, 1972, and 1976 Olympic Games, was once arrested at Wimbledon after a demonstration there.

He met last week with Joseph Carrico of Chicago, chairman of the USTA's Davis Cup Committee. "I spelled the ramifications out to him and asked for an emergency meeting of the USTA executive committee so that I could present the facts to them," Brutus told The Washington Post "but he told me subsequently that they were going ahead with the match, would not have an emergency meeting, and would not even reply to my letters."

Carrico said by telephone from Newport Beach that the USTA had given "no serious consideration whatsoever" to canceling the matches and was "concentrating on getting ready to play and leaving the matter of demonstrations to the local police organization."

The USTA has maintained for several years that any nation entering the Davis Cup should be willing to play any other nation that is admitted. Carrico last year led a drive for suspension of any nation that enters and then defaults for political reasons.

"Our executive committee voted unanimously last year, after many hours of serious discussion, that we should stay in the Davis Cup and welcome the participation of any nation. That is not construed as support for the politics of any nation we play," said Carrico.

"We can play Russia without supporting communism and South Africa without supporting apartheid," Carrico added. "We feel that we can do more for world order and peace, and frankly, more for the blacks of South Africa, by working from within rather than by throwing them out."

Carrico said that "communication in any official capacity with the people planning the demonstrations has been practically nil," and that he does not know what to anticipate when the series begins Friday at 11 a.m.

"I would assume there will be some picketing. The local police are taking precautions. They're being prudent. I think they're expecting a fairly large group and are equipped to handle anything that happens," Carrico said.

South Africa, expelled from the Davis Cup for two years, was readmitted and won the cup in 1974 when India refused to play the final, the only time in the 77-year history of the competition that a nation has won by default.

Chile eliminated South Africa in 1975 and 1976 after Mexico, conqueror of the U.S. both years, defaulted to the South Africans. The U.S. has never played South Africa.

South Africa was admitted to the 1977 competition by vote of the Davis Cup nations in London last July and again was assigned to challenge in the American Zone of the 60-nation competition.

The U.S. team of Brian Gottfried, Roscoe Tanner, Stan Smith and Bob Lutz should have little trouble disposing of the South African quad (Bernie Mitton, Frew McMillan, Byron Bertram and Ray Moore) in the best-of-five-match series, to be played on a fast cement court surrounded by makeshift stands seating 7,000.

The winner will play South Section champion Argentina in the American Zone final at Buenos Aires, April 29-May 1. The victor then plays Eastern Zone champion Australia to determine who will face the European champion in the cup final.

The draw for the weekend matches will be made at noon Friday. Tanner and Gottfried, who has won four tournaments and 40 of 44 singles matches this year, are expected to play singles for the U.S., with Smith and Lutz teaming in the doubles.

Two singles matches will be played Friday and Sunday, with the doubles on Saturday. South African captain Claude Lister is expected to name Moore and either Mitton or McMillan to play singles.

Freddie McNair of Chevy Chase said he had hoped that he and partner Sherwood Stewart, ranked No. 1 in the U.S. in doubles, would be named to the team, but that U.S. captain Tony Trabert chose second-ranked Smith and Lutz because they gave him greater flexibility in singles.

Tanner, hampered by an ankle injury, has not been in top form since winning the Australian Open at the start of the year. When Trabert named his team last Sunday, he wanted the option of having either Smith or Lutz play singles if Tanner did not do well in practice.

Italy defeated Chile, 4-1, in the 1976 final at Santiago in December and became the seventh nation to hold the sterling punchbowl launched by Dwight Filly Davis in 1900 at the International Lawn Tennis Challenge Trophy. The United States has won 24 times; Australia, 23; Great Britain, nine; France, six; South Africa, Sweden, and Italy, once each.

The U.S. won five straight years, 1968-72, but lost the final to Australia, 5-0, in 1973, the first year that all professionals were eligible to compete. The U.S. failed to get beyond the second round of the American Zone the last three years.

In the 1977 competition, begun last fall, the U.S. has beaten Venezuela and Mexico, both by 4-1 scores. The current squad is the same that beat Mexico in December, except that Gottfried has replaced Arthur Ashe, who is recuperating from surgery on his heel.