For Obama, retooling on this scale does not come naturally or happily. Among the hallmarks of his political career has been constancy: a tight and basically static cadre of close advisers and a stubborn resistance to calls for midcourse corrections. Yet in a series of interviews in early January with senior White House officials and many of Obama’s closest confidants outside the building, a picture emerged of a president engaged in a searching, clear-eyed, and sometimes painful process of self-scrutiny, and now determined to implement a plan to fix what has ailed his enterprise—and himself.