By 11:15 yesterday morning, the witnesses at a Senate Judiciary Committee hearing on the proposed FBI charter were answering questions from staff members. There wasn't a senator in sight.

Sen. Edward M. Kennedy (D-Mass.), the committee chairman and a leading proponent of the bill, was on Capitol Hill yesterday, but was busy with other Senate business, a spokesman said.

Last week Kennedy missed the conference committee meetings on two other bills the authorizations for the Justice Department and the Law Enforcement Assistance Administration -- another pet Kennedy project -- because he was announcing the start of his presidential campaign.

During that opening campaign swing, Kennedy blasted Carter for lack of leadership and cited the president's failure to take initiatives in criminal justice programs. White House press secretary Jody Powell shot back that it was Congress and Kennedy's committee that had failed to act.

It is clear that the Carter camp will be watching to see whether Kennedy can find enough time between trips to Iowa and New Hampshire to exert the kind of leadership the senator claims is lacking in the president.

Kennedy aides are confident their chairman will be around when he's needed. He plans to lead mark-up sessions on the revised criminal code and an important oil merger bill next week, a key staffer said yesterday.

But the FBI charter now seems a likely casualty of election-year politics, according to several close observers of the bill. "It's dead the water unless leadership is exerted," said Jerry Berman, Lobbyist for the American Civil Liberties union.

"We were counting on the active participation of the principals, but the coming election year seems to have made that impossible," he added.

The charter faced troubles long before Kennedy decided to challenge Carter, according to most of those involved. Several Republican senators have expressed concern that the bill might handcuff the FBI. The ACLU and other civil liberties groups have criticized the charter from the other direction and demanded such additions as civil remedies for possible future victims of FBI abuse.

But the charter also was one of the few bills -- with the criminal code and LEAA -- that chairman Kennedy decided to keep at the full committee so he and his staff could control their shaping. The LEAA bill has passed and Kennedy "will devote as much time as he needs to" on the code, a top aide said.

The FBI charter, though, languishes. Kennedy said at the first committee hearing on the bill in August, "I pledge my energies and my efforts to work. . . to insure that this legislation is enacted into law."

The senator has chaired four key sessions of the charter hearings, according to an aide, while leaving 10 others to other committee members who wanted to explore issues of personal concern.

Yesterday for instance, Sen. Strom Thurmond (R-S.C.), the ranking minority member, led questioning for a while on the FBI's ability to make background checks of government employes.

Another senior Kennedy committee aide said he recognized that the campaign will cut deeply into the time the senator can devote to the committee and his priority bills. "Sure, he'll have to work compactly and be scheduled tighly. But when it's key, he won't desert these bills, he'll be here."

Others wonder, though, if the time for Kennedy to show his clout on the charter is already passing.

Few senators have attended the hearings and the momentum present at the start has dissipated, these participants say.

"It's been critical from the beginning that Chairman Ted run the show," one said. "Now, without him, who will fill in? Who will create the new momentum?"