Wolin, 51, has been on the job since May 2009 and is widely expected to depart in the coming months. His time as Treasury's No. 2 has spanned the period of financial-crisis firefighting (the 2008 bank-bailout program, known as TARP, was a focus at his confirmation hearing) to this spring's scandal surrounding the IRS's scrutiny of conservative political groups. Wolin has bitten back at critics during these tumultuous times to defend the administration's work; in 2011, as Treasury and other financial regulators worked to implement the contentious Dodd-Frank law, The Huffington Post dubbed Wolin Treasury's "pit bull" for his blunt and confrontational style. (Afterward, The Wall Street Journal reported that amused Treasury officials presented Wolin with a dog dish in honor of the new moniker.) This is Wolin's second tour of duty at Treasury; during the Clinton administration, he was the agency's general counsel. He spent the Bush years in the private sector, at the Hartford Financial Services Group, ultimately becoming president and chief operating officer of its property- and casualty-insurance operations. Wolin grew up in Evanston, Ill., and attended Yale as an undergraduate. He received an M.S. in development economics from the University of Oxford before returning to New Haven, Conn., to earn a J.D. from Yale Law School. He has practiced law in Washington.