Former Internal Revenue Service official Lois Lerner speaks March 5 on Capitol Hill during the House Oversight and Government Reform Committee hearing on the the agency's targeting of Tea Party groups. Lauren Victoria Burke/AP hide caption

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Former IRS official Lois Lerner raises her hand as she's sworn in Wednesday at the start of a House Oversight & Government Reform Committee hearing. She declined to answer questions posed by Chairman Darrell Issa, invoking her Fifth Amendment right. Chip Somodevilla/Getty Images hide caption

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Conservatives have criticized the new Internal Revenue Service rules for political dark money as an Obama administration attempt to gain political advantage. Susan Walsh/AP hide caption

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Rep. Darrell Issa, a California Republican and chairman of the House Oversight and Government Reform Committee, planned to hold at least four field hearings on the Affordable Care Act, which he blames for increased health insurance prices. Mark Wilson/Getty Images hide caption

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It would be a vast understatement to say that Republican Rep. Darrell Issa (right) of California and Democratic Rep. Elijah Cummings of Maryland don't see eye to eye on the IRS scandal's latest development. J. Scott Applewhite/AP hide caption

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Lois Lerner, head of the IRS unit that decides whether to grant tax-exempt status to groups, leaves after being dismissed from a House Oversight and Government Reform Committee hearing on Wednesday. J. Scott Applewhite/AP hide caption

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Veteran USPS letter carrier Michael McDonald gathers mail to load into his truck before making his delivery run in the East Atlanta neighborhood on Thursday, Feb. 7, 2013, in Atlanta. David Goldman/AP hide caption

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