President Obama’s Health and Human Services Secretary Kathleen Sebelius, who oversaw the disastrous rollout of the Affordable Care Act, is resigning after a five-year tenure. Sebelius came under intense criticism following the technical problems that plagued the launch of the healthcare law. On Thursday, Sebelius said about 7.5 million people have now signed up for insurance through the new private marketplaces. Today Obama is nominating Sylvia Mathews Burwell, director of the Office of Management and Budget, to replace Sebelius.