Everyone likes Bernie. Honestly! Even, they say, if he is like your father’s childhood friend who sits at the dinner table after everyone has had a second cup of coffee to continue his rant about the earned-income tax credit.

“It’s totally positive. It is not negative toward anyone else,” said Senator Barbara Boxer, Democrat of California, an early endorser of Mrs. Clinton. “That’s the difference between our side and theirs. Also, don’t forget many of us did serve with Hillary in the Senate, so there’s a lot of history there.”

(Ms. Boxer did not point out that she has served longer in the Senate with Mr. Sanders — nine years and counting — than she did with Mrs. Clinton. But never mind.)

Democrats say they find Mrs. Clinton — the former first lady, senator from New York and secretary of state, who has raised millions of dollars for them over the years — simply more qualified and more electable. Their position is underscored by Mrs. Clinton’s 47-percentage-point trouncing of the self-described democratic socialist in the South Carolina primary on Saturday. Mrs. Clinton prevailed in three of the first four primary states.

“Before I endorsed Hillary I spoke to Senator Sanders out of respect,” said Senator Chris Coons, Democrat of Delaware. “I think he is passionate about income inequality. I just think that Secretary Clinton has a unique set of experiences and insights to be the next president.”