Representative Robert Livingston — The Livingston Group, L.L.C.

• Number of Clients: 50
• Total Amount Clients Paid Firm: $6,510,000
• Average Amount Each Client Paid Firm: $130,200
• Number of Fortune 100 Clients: 3
• Notable Clients: Oracle; Mayo Clinic; Accenture

As a former chairman of the House Appropriations Committee, who almost became House speaker—the Louisiana Republican was well-versed in the art of doing favors for colleagues. He has traded in on that experience while becoming one of Washington’s premier lobbyists, concentrating on foreign-policy work among other areas. His firm boasts of having played a lead role in approving a U.S. free-trade agreement with Morocco, as well as obtaining money for international assistance with several countries. The firm also has done considerable lobbying on behalf of Egypt. Livingston’s firm once represented Libyan leader Muammar Gaddafi’s government but terminated that relationship in 2009, two years before Gaddafi was toppled from power. But the firm stays busy in other areas as well: Its current top clients include the Fortune 100 companies Oracle and Verizon Wireless; and it brought in more than $6.5 million through the third quarter of 2011.