Harkin was asked to lead the group’s efforts on prevention and public health. Sens. Barbara Mikulski, D-Md., and Hillary Clinton, D-N.Y., were also asked to be a part of the effort.

Doctors and business and consumer groups are gearing up for an effort to improve care and bring about 46 million uninsured people into the system, something Obama and Clinton made centerpieces of their presidential campaigns.

And lawmakers on Capitol Hill are lining up to try to lead what is expected to be a long but high-profile legislative campaign.