Democratic officials say Vice President-elect Joe Biden's chief of staff will be Ron Klain. He's no stranger to the White House. He was vice presidential chief of staff to Al Gore in the administration of President Bill Clinton. Klain helped Biden prepare for the vice presidential debate during the fall campaign. Before that, Klain was among the influential Democratic advisers Biden surrounded himself with during his own Democratic primary bid. Democratic officials spoke on the condition of anonymity because they weren't authorized to speak publicly for President-elect Barack Obama's transition team. That group was preparing to announce senior staff appointments later this week.