Senator Dianne Feinstein, Democrat of California, also appeared on the show, defending Mrs. Clinton after a damaging report from the State Department’s inspector general about her use of a personal email server.

“Hillary herself has said, ‘Yes, I made a mistake. If I had a chance to do it over again, I’d do it differently.’ I mean, what do people want?” Senator Feinstein said. “This goes on and on and on. We’re reaching the final stages of a primary. Hillary Clinton is going to win this primary. I say enough is enough.”

Ms. Feinstein, a Clinton supporter, also expressed frustration, as she has in private, about Senator Bernie Sanders’s aggressive campaign against Mrs. Clinton in spite of the fact that he trails her significantly in the delegate count.

“He ought to be able to read the signposts as well as anybody else. And if he did that, he would know that it’s all but over,” she said. “So, the question comes, you know: Why doesn’t he do those things which bring all Democrats together so that we can have a convention that’s positive, not negative — so that we can have a platform that all this great, wide, broad-based party can say: ‘This is my platform. I am proud of it.’? And the Democrats together can march to victory in November.”

Mr. Sanders himself seemed less than ready to start the unifying the party.

“The inspector general just came out with a report; it was not a good report for Secretary Clinton,” he said on CBS’s “Face the Nation.” “That is something that the American people, Democrats and delegates are going to have to take a hard look.”

He also said that he would not try to sway superdelegates in states where Mrs. Clinton had won the popular vote in primary contests, but he expressed his usual frustration that many superdelegates had given their support to Mrs. Clinton before the voting began.

“That’s not rigged,” he said. “I think it’s just a dumb process which has certainly disadvantaged our campaign.”