President-elect Barack Obama may have defeated the politician most widely known as a pit-bull, but his new White House chief of staff has also garnered the reference in the past.

Rahm Emanuel, an Illinois congressman who was most recently the fourth-highest ranking Democrat in the House of Representatives is known for driving a hard deal on Wall Street as well as on Capitol Hill. Rep. Emanuel left President Bill Clinton´s White House in 1998 to work for the investment firm Wasserstein Perella & Co., which was later sold to Dresdner Bank and became Dresdner Kleinwort.

This Fortune Magazine profile of Rep. Emanuel from 2006 describes his prosperous years as a dealmaker for the firm: "According to congressional financial disclosures, he earned more than $18 million during that period. His deals included Unicom's merger with Peco Energy and venture fund GTCR Golder Rauner's purchase of SBC subsidiary SecurityLink. But friends say his compensation also benefited from two sales of the Wasserstein firm itself, first to Dresdner Bank and then to Allianz AG."

Rep. Emanuel´s Wall Street knowledge could come in handy. Last month, as House Democrats celebrated the passage of the bailout bill on the second try, Speaker Nancy Pelosi, D-Calif., praised Rep. Emanuel for contributing his Wall Street savvy to the effort. He remains well connected to his former colleagues. Investment bankers counted among the donors to his congressional campaigns, and Rep. Emanuel described himself to American Banker as having been long-time buddies with JPMorgan Chase CEO Jamie Dimon (also a contributor to his campaign this year).