By most any measure, the secretary of education is one of the least powerful cabinet positions. The secretary is 16th in the line of succession to the presidency. Education accounts for a paltry 3 percent of the federal budget, compared with 24 percent for Social Security and 16 percent for defense. And the most recent major federal education law curtailed Washington’s role on testing, standards and accountability, turning much of the firepower in education policy back to states and school districts.