A decade ago, Republicans were vying to eliminate the Education Department, deriding it as a wasteful expansion of federal authority.

Today, they led a ceremony outside its headquarters here not only to celebrate the department, but to name the building after a trademark big-government Democrat: Lyndon Baines Johnson.

“Forty years ago,” Education Secretary Margaret Spellings said at the sun-splashed ceremony, describing her department’s humble beginnings, “Education was just beginning to transition from being a small office dedicated to gathering statistics.”