The devotion of Nancy Reagan

Throughout their 52-year marriage, Nancy Reagan was President Ronald Reagan's staunchest supporter. But one of the great mysteries is that a woman who was so attuned to and protective of her husband's public image could be unaware of her own. "60 Minutes" correspondent Lesley Stahl talks with Washington Post columnist Karen Tumulty, author of the new book "The Triumph of Nancy Reagan," and with former Reagan White House chief of staff James Baker, about the complicated persona of the woman who had the most significant influence on President Reagan.