The good news for Sen. Edward M. Kennedy (D-Mass.) is that the local interviewers have stopped asking Chappaquiddick questions. The bad news is that they have substituted a line of questioning he likes even less.

At every stop these days, the dogged presidential campaigner takes time for a half-dozen interviews with local broadcast outlets -- the poor man's substitute for paid advertisements -- and in every one the same questions dominate.

"Senator, will you drop out if you lose the June 3 primaries?"

"What will you do if President Carter gets a majority of the delegates?"

"Won't you hurt your party if you stay in the race?"

Kennedy and his staff have been looking for an attention-getting way to deal with questions like that. Late today, it appeared that they would try to do so in a "major speech" scheduled for Cleveland Thursday morning.

A Cleveland gambit came to mind because it offers a new opportunity for the one thing that seems to get Kennedy national media attention now -- a thrust-and-party with President Carter. Carter is to fly to Ohio Thursday in his first admittedly political trip of the year. Kennedy would like to propose something in his 9 a.m. speech that Carter will have to respond to when he steps off his plane at noon.

Accordingly, Kennedy today tentatively scrubbed the foreign policy address he had originally planned for Cleveland, and spent the day working, between interviews, on a new speech that he said would deal with "the domestic political scene."

But the candidate and his speech-writers were evidently struggling to find a new proposal to make about the political scene. Would it be another conditional offer of a Kennedy withdrawal? An open call to Carter-pledged delegates to break with the president? The discussions went on all day and into the night.

The uncertainty reflected the Kennedy campaign's general state of confusion on the question of what to do after June 3. Kennedy has focused so intensely on next Tuesday's major primaries, his staff said, that there is a conspicuous lack of consensus about his course thereafter and plans for the Democratic National Convention in August.

Kennedy can fairly say, though, that he is not the only person unclear about the future. Nobody in the Democratic Party, including the experts who are paid by the candidates to scope out such things, seems to have the foggiest notion about what kind of convention it will be.

The president's managers concede that Kennedy will have enough delegates -- at least 40 percent of the convention -- to unsettle things considerably if he chooses to. Some top Carter aides are complaining, with unconcealed bitterness, that it is essentially up to Kennedy to determine whether the convention becomes a fraternal gathering or a battleground.

Carter workers profess to be only mildly worried about the prospect of a Kennedy coup -- a rules fight or platform debate that turns into an open mutiny against the incumbent. Still, the campaign is investing time and money in a computerized surveillance operation to detect defections by Carter-pledged delegates.

That "rules fight" business, by the way -- a plan under which Kennedy forces bring a challenge on the convention floor to overturn the party rule requiring delegates to honor their pledges at least through the first ballot -- is something you don't hear about much these days at Kennedy headquarters.

The campaign's political director, Paul Kirk, has passed the word that the "rules fight" gambit is not an appropriate topic for public discussion. And Kennedy eschews any knowledge of such a fight. "I haven't given any personal thought to it," the candidate said during a luncheon at The Washington Post on April 14.

But it was Kennedy, in an interview on March 19, the day after his huge loss in the Illinois primary, who first raised the possibility of a rules contest.

"Mathematics, you know, is one of the great myths, for any of us who have been to these conventions," he said then. "You have to take a look at the rules, you have to see how many of these delegates can pass on the first ballot . . ."

To anyone who is still seriously thinking about making Kennedy the Democratic nominee -- and most of his campaign staff still seems to consider that a reachable, if distant goal -- some convention contest that will result in a change of the rules, permitting Carter-pledged delegates to switch to Kennedy, is essential.

If Carter is ahead by 500 delegates or so at convention time, the Kennedy people probably won't bother. But if Kennedy goes to New York a few hundred delegates behind, convention fireworks are likely.

Carl Wagner, a veteran of conventions past, is setting up a floor-manager apparatus to implement Kennedy's convention strategy. But so far Wagner cannot say what the strategy, if any, will be.

"It's very, very dicey 90 days before a convention to predict what's going to happen," Wagner said.

Kennedy's chief issues analyst, Peter Edelman, has been working on a Kennedy version of the platform, and has been thinking about where a platform fight may come.

"I think that Kennedy will want to have wage and price controls in the platform," Edelman says. "I think he's going to want language about unemployment and interest rates -- the way Jimmy Carter has fought inflation. We're going to be interested in energy issues, Kennedy's gas rationing proposals versus Carter's method, if it is a method, to ration by price.

"I think we would definitely want the platform to endorse comprehensive health care, because Carter's proposal is just not adequate. And we will want language on the budget cuts and defense spending."

Neither campaign seems certain at this point whether Kennedy's platform efforts will lead to a squabble at the convention. "It's quite possible that everything will be compromised before the convention starts," Edelman says.

Carter's strategists have not decided whether to fight or fold on the platform if Kennedy raises the issues Edelman is talking about. It is not unthinkable that Carter would simply give in. His record in office shows that he does not consider the party platform binding on him.

The 1976 Democratic platform called for continued price controls on oil and gas; Carter decontrolled both commodities. The platform called for strict controls on some handguns; Carter this year sent his son to New Hampshire to tell gun owners that he opposes gun controls. The platform savaged Republican presidents for raising the defense budget in peacetime; Carter has done the same thing, and he calls it one of his major accomplishments.

In his own presentation to the platform committee in 1976, candidate Carter said he would fight inflation through "low interest rates" and "standby" authority for wage and price controls. His administration's anti-inflation program helped raise interest rates to record levels, and he now says that controls would be wrong.

One factor mitigating against a platform fight, however, is that the man who would have to instigate it, Kennedy, doesn't seem very enthused about the idea. "Sure, I think we can get a lot into that platform," he said with a shrug two weeks ago. "The question is, does it mean anything?"