With 65,000 employees and a budget of $707.7 billion, the Department of Health and Human Services accounts for nearly one-quarter of all federal spending, second only to the Defense Department. And in the Obama administration the job is taking on a daunting responsibility: shepherding healthcare reform legislation through Congress. Unlike his predecessors, Thomas A. Daschle, President-elect Barack Obama's choice for HHS secretary, will be given an expanded role to lead the administration's efforts to overhaul the U.S. health system.