Committee Chairman Rep. Darrell Issa (R-Calif.) is seen during the House Oversight and Government Reform hearing called "The IRS: Targeting Americans for Their Political Beliefs," on Capitol Hill in Washington, Wednesday, May 22, 2013.  (Drew Angerer for The New York Times)

J. Russell George, the Treasury inspector general for tax administration, confers with an aide during a House Oversight and Government Reform hearing examining the IRS's targeting of conservative groups, on Capitol Hill in Washington, May 22, 2013. (Drew Angerer for The New York Times)

Rep. John Mica (R-Fla.) questions witnesses while he holds up a chart during the House Oversight and Government Reform hearing examining the IRS's targeting of conservative groups, on Capitol Hill in Washington, Wednesday, May 22, 2013. (Drew Angerer for The New York Times)

Lois Lerner, director of Exempt Organizations for the Internal Revenue Service, leaves the room after invoking her Fifth Amendment right not to testify during a House Oversight and Government Reform hearing on Capitol Hill in Washington, May 22, 2013. Lerner, the IRS official who tried to temper efforts to target conservative groups and then made the issue public, told her questioners that allegations she had misled Congress in previous testimony were false before refusing to answer more questions.  (Drew Angerer for The New York Times)