In selecting Tom Daschle to be his health and human services secretary, President-elect Barack Obama said Thursday that he wanted Mr. Daschle, a former South Dakota senator, to pursue something that had eluded federal officials for decades: securing affordable, accessible health care for every single American. Whether Mr. Daschle, a former Senate majority leader, can succeed where others failed is unclear. Year after year, Mr. Obama said, "our leaders offer up detailed health care plans with great fanfare and promise, only to see them fail, derailed by Washington politics and influence peddling." Even Mr. Daschle, who will also be director of a new White House Office of Health Reform, acknowledges that the task will be difficult. In a recent book, he portrays the health care industry as a collection of special interests and predicts they will wage all-out war to defeat reform. Mr. Obama said Mr. Daschle, as head of the new office, would be the lead architect of proposals to expand coverage and rein in health costs.