WASHINGTON — President Obama’s pick for health and human services secretary, Tom Daschle, failed to pay more than $128,000 in taxes, partly for free use of a car and driver that had been provided to him by a prominent businessman and Democratic fund-raiser, administration officials said Friday.
....
The committee report said Mr. Daschle had told the committee staff that “in June 2008, something made him think that the car service might be taxable, and he disclosed the arrangement to his accountant.”
....
The committee report said, “Senator Daschle filed the amended returns voluntarily after Barack Obama announced his intention to nominate the senator to be the secretary of health and human services.”
....
http://www.nytimes.com/2009/01/31/us/politics/31daschle.html?_r=1&hp

So he figured out that he cheated on his taxes in 6/08, and actually filed the amended returns AFTER he was going to be nominated.