When Sen. Edward M. Kennedy says the biggest problem with President Carter's anti-inflation program is that "people don't know whether it is Mr. Kahn's or the president's," he is tipping a presidential campaign tactic to protect his own greatest weakness.

Kennedy told us voluntary guidelines are failing because the public perceives them as the creation of anti-inflation czar Alfred Kahn, rather than Jimmy Carter. Since the failure then becomes one of leadership and not policy, Kennedy has no need to embrace the radical alternative proposed by many of his most fervent supporters: wage-price controls.

In an hour-long interview with us, Kennedy shield away from attacking Carter on economic, energy and foreign policies. The harsh anti-Carter rhetoric of last winter had melted into wordy generalities about leadership. The White House and the Republicans, poised to attack Kennedy as a doctrinaire liberal out of touch with the times, will find Ted Kennedy is no George McGovern.

What's more, even the most emotionally liberal Kennedy-backers are willing to excuse centrist deviationism. That he can maintain hard-core activists while appealing to the great center bolsters his heavy advantages against Carter. While the White House insists the prospective race is closer than the press suggests, in fact it is probably more one-sided.

Kennedy's personal political assessment was made in chats with associates this past summer. He confided that his overriding political problem was neither Chappaquiddick nor personal problems that face his wife, but his liberal positions that conflict with the current mood. This week's Boston Globe poll, showing a decline in Kennedy's massive New Hampshire strength when he is identified as a big spender, confirms his assessment.

Kennedy's remedy to avoid being McGovernized is clear from the way he sidesteps the wage-price controls that many of his boosters (especially in the labor movement) had expected. Under our questioning, he steered away from firm policy stands. While Ronald Reagan attacked President Gerald Ford only after challenging him, Kennedy's approach to Carter is exactly the opposite.

On Jan. 13, Kennedy accused the president of a "seriously defective" approach to the federal budget that favors the rich over the poor. Last week, he told us he basically favors Carter's relatively stringent fiscal policy ("though with some priorities revised").

On May 12, Kennedy called the president's oil price decontrol "incredible," asking: "Is it fair to ask the poor elderly citizens . . . to shift to cat food so they can afford to pay their heating bills?" Now, while still pushing his own energy package, he has shelved the crusade against oil decontrol.

On Jan. 21, he accused the Carter administration of juggling figures to shield excessive defense spending. Last week he told us he generally favors Carter's claimed 3 percent rise in real defense spending. While on Jan. 21 he charged Carter's proposed new MX missile could "increase the threat of nuclear lar," he told us last week he favors "development but no deployment" of the MX.

On foreign policy, Kennedy told us he had only "tactical" differences with Carter. On tax policy, he opposed personal income tax cuts and the proposed value-added [sales] tax but said "at a later date" he might support tax incentives for capital formation and suspension of Social Security tax increases-- a policy identical to the president's.

Does Kennedy's bland neu ideology turn off such early supporters as New York State Attorney General Robert Abrams and his political lieutenant, Ethan Geto, originally attracted by Kennedy's support for an "urban agenda"? Not at all, even though they are among the nation's most advanced liberals.

"We're willing to accept the senator moving toward moderate positions," Geto told us. Similarly, one prominent Midwestern liberal who lill back Kennedy told us: "I don't think doctrine is what people are looking for. They're looking for leadership."

Lt. Gov. Mario Cuomo of New York, one of the nation's most ardent Carter loyalists, is saying there's not a dime's worth of difference doctrinally between Carter and Kennedy, adding: "Who do [the people] want as a new leader-- Kennedy, Connally or Benito Mussolini?"

However, the president's men are going in precisely the opposite direction, labeling Kennedy a wild spender who would not win a state south of Kentucky. That is indeed the only chance to stop Kennedy in any early primaries, but he is making it difficult by quickly turning toward the center. Copyright 1979, Field Enterprises, Inc.