The press conference at Main Justice last week was supposed to be about health care fraud enforcement, but Attorney General Eric Holder Jr. could tell the throng of reporters had other topics on their minds. "There are more cameras here than usual," he said wryly.

Until that afternoon, Holder had remained ­largely out of the Washington spotlight since President Barack Obama’s re-election. Holder’s second term at the helm of the U.S. Department of Justice had attracted little attention from Republican critics on Capitol Hill.