J. SCOTT APPLEWHITE / AP
Lois Lerner, head of the IRS unit that decides whether to grant tax-exempt status to groups, listens Wednesday at the start of a House Oversight and Government Reform Committee hearing to investigate the extra scrutiny the IRS gave to tea party and other conservative groups that applied for tax-exempt status.
Moving quickly to stem a raging controversy, the new acting head of the Internal Revenue Service started cleaning house Thursday by replacing the supervisor who oversaw agents involved in targeting tea party groups.