An army of workers and volunteers has fanned out around the country trying to enroll young and healthy people in health insurance now available through President Barack Obama's signature law.
Run largely by groups with close ties to the White House, the on-the-ground effort is based in part on lessons learned from Obama's two presidential bids, which revolutionized the way campaigns tracked and targeted voters.
More than any other group, participation from the so-called young invincibles will be crucial to the health law's success.
The Kaiser Family Foundation estimates that about 40 percent of those who enroll need to be young and healthy to balance the higher costs of insuring older, sicker people.
With less than two months until the sign-up deadline, the Obama administration is lagging behind its goal.
Explore further: For Obama, a frustrating health care rollout (Update)