“Michelle Obama: The First Lady the World’s Been Waiting For,” trumpeted Vogue’s March 2009. In the two short months after her husband’s historic first inauguration, Mrs. Obama had already begun redefining the role, from dressing to dazzle at official events to rolling up her sleeves to plant the White House’s first vegetable garden since World War II. In the years since, she has continued to push the boundaries of what a First Lady can be and do, charming the public with her high-wattage TV appearances, good-humored “Mom dancing” moves, and family-focused initiatives to combat childhood obesity. For her husband’s first inauguration, she picked the Cuban-born designer Isabel Toledo; for the second inauguration, Thom Browne, a menswear veteran; and for both inaugural balls, she bestowed bragging rights on the young designer Jason Wu. “Mrs. Obama’s support fulfills the American Dream of young designers,” Wu told Vogue. “She has single-handedly brought a newfound excitement and energy to the fashion industry.”