Todd Purdum writes at Vanity Fair:
The days when presidential Cabinets contained the likes of Thomas Jefferson as secretary of state, or Alexander Hamilton as secretary of the Treasury, are long since gone (and those early Cabinets displayed a fractiousness that no modern president would be likely to tolerate), though Cabinet officers retain symbols of office—from flags to drivers to, in some cases, chefs—befitting grander figures. The lingering public image of Cabinet meetings as the scene of important action is largely a myth. “They are not meetings where policy is determined or decisions are made,” the late Nicholas Katzenbach, who served Lyndon Johnson as attorney general, recalled in his memoirs. Nevertheless, Katzenbach attended them faithfully, “not because they were particularly interesting or important, but simply because”—remembering L.B.J.’s awful relationship with the previous attorney general, Bobby Kennedy—“I did not want the president to feel I was not on his team.” Even as recently as the 1930s, Cabinet figures such as Labor Secretary Frances Perkins, Interior Secretary Harold Ickes, and Postmaster General James A. Farley were important advisers to Franklin D. Roosevelt (and, in the cases of Perkins and Ickes, priceless diarists and chroniclers) in areas beyond their lanes of departmental responsibility, just as Robert F. Kennedy was his brother’s all-purpose sounding board and McNamara provided J.F.K. with advice on business and economics well outside his purview at the Pentagon. “Cabinet posts are great posts,” says Dan Glickman, who was Bill Clinton’s agriculture secretary. “But you realize that the days of Harry Hopkins and others who were in the Cabinet and were key advisers to the president—that really isn’t true anymore.”
The sharp growth in the White House staff in the years since World War II has also meant that policy functions once reserved for Cabinet officers are now performed by top aides inside the White House itself. Obama meets regularly and privately with Tim Geithner and Hillary Clinton, but almost certainly sees his national-security adviser, Tom Donilon, and his economic adviser, Gene Sperling, even more often. The relentless media cycle now moves so swiftly that any president, even one less inclined toward centralized discipline than Obama, might naturally rely on the White House’s quick-on-the-draw internal-messaging machine instead of bucking things through the bureaucratic channels of the executive departments.