“People are jockeying like mad but they have to be careful because to some degree this administration has frowned on explicit, overt jockeying,” said a former Obama administration official. Similarly, word has gone out to donors from Mr. Romney’s Boston headquarters not to ask for jobs until after the election.

Most intense has been the struggle to succeed Secretary of State Hillary Rodham Clinton, who is stepping down. On the Democratic side, Susan E. Rice, the ambassador to the United Nations, was the clear front-runner for months. After the deadly attack on a Libya diplomatic post, the White House sent her to the Sunday television programs, raising her prominence for a possible promotion. But the move backfired when she described the assault as an outgrowth of protests only days before the government shifted its explanation and called it a terrorist attack.

Mr. Kerry signed letters to the administration requesting information about the attack but issued a statement defending Ms. Rice. It is a mark of Washington cynicism that even a statement defending her was seen by some as an effort by Mr. Kerry to undercut her by keeping attention on the matter. The Obama team has rallied behind Ms. Rice, saying she reflected information from intelligence agencies, but it recognizes that she now could face a confirmation fight from Senate Republicans.