The two weeks of stumbling following the shock of the interview "Teddy" on CBS have so debilitated Sen. Edward Kennedy's supposed political domination in New York that sharp-tongued Gov. Hugh Carey privately calls him a "plummeting star."

Kennedy's ineptitude on the network documentary, followed by incompetence and neglect in his campaign's early days, has transformed the political landscape here. Neither Carey nor Sen. Daniel Patrick Moynihan, seemingly sure Kennedy boosters, has endorsed him. While President Carter's operatives round up organization Democrats, Kennedy's men have offended both centrists and reformers.

None of this would likely keep Kennedy from beating Carter if New York's Democratic primary were held today, but politicians think it could make things close next March 25. Apart from exposing Kennedy campaign blunders, that raises serious questions whether Kennedy can unite the two rival Democratic constituencies in this and other northern industrial states.

Party unification seemed Kennedy's long suit during last summer's heady days when reformist and centrist Democrats, usually gouging out each other's eyes here, coalesced for him. Agents of Sen. Moynihan and his antithesis, state Attorney General Robert Abrams, collaborated to fix a primary date least in Carter's interest.

This common purpose did not long survive Kennedy's answers to CBS correspondent Roger Mudd Nov. 4. Whatever its impact on rank-and-file voters, Kennedy's incoherence stunned New York's Democratic elite. Little else has been talked about since, even by his own supporters.

It is the first TV documentary that blocked a governor's endorsement. Carey abruptly changed course, commenting widely on Kennedy's poor performance. By last weekend, he was making the "plummeting star" crack to aides. His endorsement is now an open question.

Sudden doubts about whether Teddy is in the same class as his brothers enlarged the importance of Kennedy's casual approach to organization. Reform Democrats were dismayed that Kennedy's man in New York was David Bartley, former speaker of the Massachusetts House, who is described in the Village Voice as "a good ol' pork-chop Democrat." Bartley is a weekend warrior, holding down his job as president of Holyoke (Mass.) Community College five days a week.

Bartley was outmatched by the temporary presence here of Carter campaign chairman Robert Strauss, who pumped the telephone to line up politicians and businessmen. With the Brooklyn regular organization about to join Queens and the Bronx in the president's corner, local Kennedyites began to panic.

The response somewhat reassured reformers but alarmed Moynihan's wing of the party. State committeewoman Barbara Fife, running Kennedy's campaign office, is anathema to the centrists. Sending down liberal state Rep. Barney Frank of Massachusetts to help out Bartley on a full-time basis was an affront to Moynihan. At this year's Americans for Democratic Action banquet in Washington, Frank introduced ex-ambassadors and other assorted notables before getting around to mentioning the only U.S. senator present: Pat Moynihan. It was a snub Moynihan has not forgotten.

Nor has Moynihan forgotten opposition to his 1976 Senate bid by Peter Edelman, then Carey's state youth director and now a top Kennedy campaign staffer in Washington. One prominent New York Democrat who is close to Moynihan told us: "Kennedy's campaign is being run by the upper-class new left. Kennedy is giving signals to the people in the center of the New York state Democratic Party that if he wins, they're finished."

When Kennedy walked over to Moynihan's office in Washington Nov. 2, it was expected that he would return with an endorsement. Instead, Moynihan declined an invitation to Kennedy's Nov. 7 announcement of candidacy. Overtures to sign up Moynihan's top aide, Tim Russert, met the response that he would not move until and unless the senator did.

Endorsements by local politicians were viewed as superfluous by Kennedy insiders when they considered their charismatic candidate a certainty in New York against poor Jimmy Carter. That Sunday night on CBS changed everything. Now, basic political skills will be needed, and support from Carey and Moynihan may be essential.

Carey will watch closely to see whether Kennedy is really as bad as he seemed when answering Roger Mudd's questions. (He decided there was some improvement on NBC's "Meet the Press" two weeks later). Moynihan's requirements are different: making sure that Kennedy meets his standards on Israel, defense and parochial schools, but also that his New York campaign is no haven for Moynihan's blood enemies. Kennedy has far to go to satisfy both of them.