Frankie Sojourner, a black youth hardened by the Streets of Newark, N.J., is torn between languishing in his past moments of esteem as a gang leader and trying desperately to rise above his no-win circumstances.

Dorian Harewood, protected by a Dayton, Ohio, suburb but knowing all the ambiguities and toughness of the Sojourner he brings to life in "The Mighty Gents" at the Kennedy Center, doesn't have the same kind of frustration.

At least, not now. The future appears to be his. From thenotices Harewood receied in David Rabe's acclaimed "Streamers," and the New York workshop production of "Gents," he is poised on the brink of success. And he doesn't appear locked into soem of the problems of his black acting predecessors, Sidney Poitier and James Earl Jones, who had to wait long periods between dramatic offers, and successes.

His only burdan right now, says Harewood, susing his street tough's curt, invenerable smile - a smirk that says "Babe, don't doubt my word" - is to succeed. "I am pushing to come to that higher level. What I would love to do is have a terrific career in films, theater and recording."

Such small prospects, unhesitatingly offered over eggs Benedict and four glasses of orange juice, are only a reflection of others' expectations. Harewood is currently the object of a whisper campaign, whispers that tout him as the next big star, a new Brando, a guy more versatile than Nen Vereen.

As proof that he is well-prepared for the future, this week Harewood is pening in two media: "Gents," the first drama by a black playwright ever to play the kennedy Center and "Gray Lady Down," a film with Charlton Heston and David Carradine which premieres Friday in New Yor.

Also, CBS Television has him under contract and, he says, is developing a dramatic vehicle for him. "Siege," a television movie with Martin Balsam and Sylvia Sydney. Fans like actor Tony Randall are still complaining about Harewood's not receiving a Tony nomination for Carlyle, the mean crazy in "Streamers." Randall announced the oversight on the "Tonight" show.

Because Harewood is more like the refined product of the conservatory at the University of Cincinnati than his hard roles, he is very appreciative of the raves. "But I still look at that and say it's one person's opinion. What I think of the performance is still may criterion. The thing I hate worse than being confined is conceit. I know there's a thin line between confidence and concelt," says Harewood, who has been observing the pitfalls of stardom. "When you are conceited you don't work hard. I'm working every minute." He can afford to, he's only 27 years old. a fact he doen't like to discuss, because he doesn't want ot be age-cast.

By confinement Harewood means the hemming-in of his versatility. "When I studied opera, they were trying to channel me. They would say let's try bass' and then switch to high and low baritone. I can do them all, I didn't want to learn just one," says Harewood. "Then in acting classes they had instructions for crying. I wanted to do it naturally, and all ways. That's why one of my goals right now is to learn an instrument from all the families." Harewood plays the piano, the tuba, the bass guitar, and now is learning classical guitar.

Harewood, who admires Ruby Dee, Lou Gossett and Marlon Brando, says he learned his best lesson in restraint and balance from Bette Davis. In the fall of 1974 he starred with Davis in "Miss Moffat," a play which opened and closed the same night in Philadelphia. "One night she was speaking and forgot the line that was my cue. I waited. There was that big pause. Then I decided to go out and take the brunt of what looked like my mistake. But she stopped the play and told the audience it was her fault. They stood up and applauded."

Not long after the Davis flop, Harewood also opened and closed the same night in "Don't Call Back" with Arlene Francis. For that brief Broadway appearance, he won the Theatre World Award as the most promising actor. But Harewood very gallantly doesn't count those experiences as disappointments.

Harewood says life has been very good to him. He was the fourth of six children, all well-fed and well-educated, principally because their father, a high-school teacher, held two other part-time jobs, allowing their mother to stay home. "I don't know how he did it but all his spare time was spent giving us love and affection," says Harewood. Part of his young life was spent in a suburb outside Dayton, where Harewood found the same solidarity of groups that Sojourner of "Gents" found in Newark.

"We used to do all the normal stuff, hang out on the corners, crash a party, fight at the party. But we didn't get as far as weapon-carrying. We had first fights," recalls Harewood. He shot a lot of pool, played first-string on his sports team and wanted to sing. "We used to stand on the corner and sing 'Blue Moon' but I also learned the piano, played in the band, and won some state contests for tuba."

After high school, Harewood won a four-year scholarship to the Conservatory of Music at the University of Cincinnati, where he majored in opera. He decided the curriculum was too rigid and switched to musical theater. In due time he won the role of Judas in the national tour of "Jesus Christ Superstar," and now has racked up two movies, four Boradway plays, eight television spots and is looking for a record contract.

While he was breaking in a brand new Fender Rhodes piano - "just like Stevie Wonder's" - in his apartment in Los Angeles he was called to audition for "Gents."

Harewood's part in "Streamers" was so violent that he had nightmares.

"But Frankie has taken more out of me," he says. "it takes a lot of energy because he is carrying all the weight, the burden of frustration and desperation," says Harewood. In the end Frankie Sojourner's decision is not a heroic one. "yet he's not a negative character position, but he takes a negative position. I want youngsters to latch onto his desire to win," says Harewood, and he's hoping his audience will see the same in him.