Obama on Kathleen Sebelius: "The final score speaks for itself"

After helping President Obama shepherd through Congress his signature law and overseeing its implementation -- through the good, the bad and the ugly -- Health and Human Services Secretary is stepping down, Mr. Obama announced today.

"After five years of extraordinary service to our country and 7.5 million Americans who have signed up for health coverage through the exchanges, she's earned that right," Mr. Obama said from White House rose garden.

While millions of people have gained coverage through the Affordable Care Act on Sebelius' watch, the secretary herself said she was responsible for the botched rollout of the Obamacare marketplaces, calling HealthCare.gov a "debacle." The administration managed to recover and reach its enrollment goals for the Obamacare marketplaces, but the chaotic start to the program cast a shadow over Sebelius' five-year tenure as HHS secretary.

"Kathleen has been there through the long fight to pass the Affordable Care Act... She helped guide its implementation even when it got rough," Mr. Obama said. "She's got bumps, I've got bumps, bruises."

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At the end of the day, however, Mr. Obama said Sebelius "will go down in history for is serving... [when the U.S.] finally declared that quality, affordable health care is not a privilege but a right for every single citizen for the United States of America."

The administration "lost" the first quarter of the six-month open enrollment period for Obamacare because of the HealthCare.gov problems -- "and they were problems," Mr. Obama acknowledged.

But, he continued, "Under Kathleen's leadership, her team at HHS turned the corner, got it fixed, got the job done, and the final score speaks for itself. There are 7.5 million people across the country that have the security of health insurance, most of them for the very first time, and that's because of the woman standing here beside me."

The president also praised Sebelius for her less high-profile work. She helped expand mental health care coverage, promoted women's health, and "brought us closer to the first AIDS-free generation," he noted. Her very first task as secretary, he said, was preparing the nation for a pandemic flu outbreak.

"These are the sorts of daily challenges that Kathleen has handled -- often without fanfare, often without knowledge -- but that have been critical to the health and welfare of the American people," he said.

Still, Sebelius became the embodiment of Obamacare problems after the flawed HealthCare.gov rollout, and Republicans in the last six months have been relentless in their attacks against her and the program.

"Regardless of the administration's public explanation for the Secretary's exit, Obamacare has been a rolling disaster and her resignation is cold comfort to the millions of Americans who were deceived about what it would mean for them and their families," Senate Minority Leader Mitch McConnell, R-Ky., said in a statement.

"I knew it wouldn't' be easy," she said. "There's a reason that no earlier president was successful at passing healthcare reform despite decades of attempts."

Still, she hailed Obamacare as "the most significant social change in this country" in the last 50 years. In spite of the setbacks, she said, "We are making progress -- tremendous progress -- and critics and supporters alike are benefitting from this law."

Sebelius plans on staying at her post as HHS secretary through most of May, a senior administration official confirmed to CBS.