Liberals have grown frustrated by some of his actions, like the decision this month to drop tougher air-quality standards.

And polling suggests that the president’s yearlong effort to reclaim the political center has so far yielded little in the way of additional support from the moderates and independents who tend to decide presidential elections.

“The alarms have already gone off in the Democratic grass roots,” said Robert Zimmerman, a member of the Democratic National Committee from New York, who hopes the president’s jobs plan can be a turning point. “If the Obama administration hasn’t heard them, they should check the wiring of their alarm system.”

At a gathering of the Democratic National Committee in Chicago this weekend, some party leaders sounded upbeat after they toured the Obama campaign headquarters. But others expressed anxiety that Mr. Obama’s accomplishments were not being conveyed loudly enough to ordinary people, that Republican lawmakers were making it impossible for him to get more done, and that Mr. Obama’s conciliatory approach might be translating to some voters as weakness.

“Now that they’re slapping him in the side of the face, he’s coming back,” said William George, a committee member from Pennsylvania. “He needs to start stomping his foot and pounding the desk.” At the White House and at Mr. Obama’s campaign headquarters in Chicago, officials bristled at the critiques, which they dismissed as familiar intraparty carping and second-guessing that would give way to unity and enthusiasm once the nation is facing a clear choice between the president and the Republican nominee.

Jim Messina, the campaign manager for the president’s re-election, said the criticism was largely a “Washington conversation” that did not match up with the on-the-ground enthusiasm for Mr. Obama among his network of supporters. Yet even without a primary challenger, the campaign purposefully started its effort early to allow concerns from supporters to be aired.