Some Clinton advisers also said that the focus on Mr. Obama’s “guns or religion” comment was a way to put him on the spot with so-called values voters  in part to offset Mrs. Clinton’s baggage in this area. According to the latest New York Times/CBS News poll, conducted March 28-April 2 with 1,196 registered voters nationwide, 60 percent of them believe Mrs. Clinton shared the values that most Americans tried to live by, and 34 percent did not. Both Mr. Obama and Mr. McCain fared better, with Mr. Obama performing best  70 percent said he shared those values, and 21 percent said he did not.

Some of the uncommitted superdelegates interviewed said they were concerned about whether Mr. Obama reflected the values and interests of voters in states that Democrats aim to carry in November or hope to steal from Republicans, like some Southern states that they typically do not win in a general election. Yet they said they had had these concerns for some time  and Wednesday night’s debate had not intensified them.

“Obama argues that he will put more states in play, but I haven’t seen him put the coalitions together as strongly as we need to,” said Joe Turnham, an uncommitted superdelegate who is chairman of the Alabama Democratic Party. (Mr. Obama won the Alabama primary in February; Mr. Turnham has known the Clintons for many years.)

“You have to put together blue-collar workers, veterans, seniors and swing evangelical voters and compete in states like West Virginia, Kentucky, Arkansas, Florida, Ohio and Pennsylvania,” he added. “I feel like Hillary has shown more strength there.”

Mr. Obama sought to allay concerns about questions of his electability on Thursday. At a campaign stop in Raleigh, N.C., a woman told Mr. Obama that he was “really pummeled during the debate.” She continued, “What is your strategy to beat the Republicans in November?”

“That was the rollout of the Republican campaign against me in November. It happened just a little bit early, but that is what they will do,” Mr. Obama said. “They will try to focus on all these issues that don’t have anything to do with how you are paying your bills at the end of the month. There’s no doubt that I will have to respond sharply and crisply, then pivot to talk about what exactly are we going to do for the economy and what are we going to do about the war in Iraq.”

Until the nominating fight ends, Mr. Obama said, he is “trying to show some restraint.” He added, “I won’t have as much restraint with the Republicans."