John Sasso, who resigned yesterday as campaign manager to Massachusetts Gov. Michael S. Dukakis, rose through the ranks of hardball Massachusetts politics to become a star among Democratic political operatives -- a tough, savvy strategist considered vital to the career and presidential aspirations of his boss.

Sasso functioned in many ways as an alter ego for Dukakis, handling sensitive political dealings that the reform-minded Democratic governor often disdained.

The 40-year-old native of Paterson, N.J., has been active in politics since his student days at Boston University. His major victories include masterminding a 1978 property-tax referendum opposed by Massachusetts' commercial interests; engineering Dukakis' comeback from political oblivion in 1982, and restoring good relations between Dukakis and the Massachusetts legislature -- a relationship that had soured during Dukakis' first term as governor, 1974-78. He took time out from Dukakis' staff in 1984 to manage the campaign of Democratic vice-presidential nominee Geraldine A. Ferraro.

Political director Paul Tully, who also resigned from the Dukakis campaign yesterday, is an experienced operative, who had helped run the 1980 presidential bid of Sen. Edward M. Kennedy (D-Mass.), served as Walter F. Mondale's political director in 1984 and worked for former Colorado senator Gary Hart's ill-fated campaign this year.

In a matter of months this year, Sasso had earned his stripes as an architect of a national campaign, managing the drive that has pushed Dukakis into the first tier in the competition for the Democratic presidential nomination.

"I think there is no finer campaign manager in America," said James Johnson, who ran Mondale's 1984 campaign.

"The marks of his campaigns are discipline and cooperation," said Thomas Kiley, a Boston consultant who worked with Sasso on the 1982 Dukakis race. "He is very talented, talented in the way the Chicago Bears are talented -- a thorough job of preparation and no mistakes. It's not that he is any more brilliant than any one else . . . . he just works harder."

But Sasso has known controversy before. The disclosure of his role in the distribution of a tape comparing a speech by Sen. Joseph R. Biden Jr. (D-Del.) with a similar, earlier speech by British Labor Party leader Neil Kinnock is the second time Sasso has been involved in a campaign incident involving tapes.

In Dukakis' 1982 primary against Gov. Edward J. King, Sasso played what became known as the "sex tape" for a small group of Boston Globe reporters on an off-the-record basis. The tape, made by a Dukakis supporter, parodied a King commercial in which King's wife praised her husband for making her exercise every day while she was recuperating from polio. The parody used language from the commercial to describe King's sex life.

King learned of the parody and sent an angry letter to the Dukakis campaign. Initially, Sasso denied the existence of the tape -- "There never has been such a tape," The Boston Globe quoted him as saying -- but about six hours later, the Dukakis campaign acknowledged that "a tape unflattering to King . . . was destroyed a day after its receipt."

Tully left Kennedy's staff at the beginning of this year to become a top aide in Hart's campaign. His recruitment by the Dukakis campaign, after Hart's withdrawal, was considered a political coup among Democratic operatives.

In outlining his reasons for joining Dukakis' presidential campaign, Tully said, "I always try to go with the most liberal candidate who has a serious chance of being elected."

Since 1972, however, Tully has not had much luck, working with the presidential campaigns of then-Sen. George S. McGovern (D-S.D.) in 1972, Rep. Morris K. Udall (D-Ariz.) in 1976, Kennedy in 1980, Mondale in 1984 and then Hart.