With Obama's popularity rebounding, Democrats have been eagerly awaiting the president's return to campaigning. He'll hold his debut event for her Tuesday in North Carolina. Yet campaign officials say just as critical could be Obama's political operation. That includes deep troves of voter and donor information, and a corps of trained field staffers and volunteers.
The crown jewel of Obama's machine is a massive supporter email list that is now fully available to Clinton through the Democratic National Committee. The party recently started sending emails signed by Clinton to the entire list.