As a 27-year-old domestic policy aide to President Jimmy Carter, David Rubenstein earned a reputation for tireless dedication to his work. After leaving the White House, he brought the same inexhaustible energy to building the global private equity powerhouse known as the Carlyle Group. Over the years, former secretaries of state and defense, a former British prime minister -- even a President of the United States -- have served the group as directors or advisers. Although Carlyle earned an early reputation for expertise in defense and aerospace, its interests run the gamut: automotive and transportation, consumer and retail, energy and power, health care, telecom and media. David Rubenstein's matchless network of Washington contacts has given the Carlyle Group a powerful public image of authority and influence, but the most numerous beneficiaries of the group's investments are the millions of ordinary men and women whose pensions are invested in Carlyle funds.