Romney’s suggestion that only business owners should occupy the White House was hardly surprising; it just reinforced the reverence for builders of small businesses manifested in the Republican gathering in Tampa. But it is a curious claim nonetheless. For most of the nation’s history, lawyers, educators and military men have dominated the roster of American presidents. Voters often questioned the public spiritedness of business leaders, looking to the White House less to unleash the energy of the free market than to shield them against its vicissitudes. Romney’s campaign embodies a recent, and very different, model of presidential leadership.