It was no secret that Eric Holder's confirmation as attorney general would trigger reviews and changes to the most controversial Bush administration policies, from interrogation tactics to terrorism trials and warrantless surveillance.
But Holder's decision to investigate whether CIA officers should be prosecuted for their harsh interrogations of high-level detainees overseas has taken many by surprise and drawn strong criticism that he may be disrupting U.S. counterterrorism efforts.
"We need a CIA that's focused on keeping Americans safe and winning this war -- not worried about what politicians and the Justice Department in Washington D.C. may do to them for doing their job," Rep. Pete Hoekstra, the top Republican on the House Intelligence Committee told FOX News.
The highly controversial decision comes as the Department of Justice released a 2004 report from the CIA's inspector general detailing allegations of harsh interrogation practices -- which Holder cited in his decision.
Now Holder is being assailed by very prominent conservative voices, including former Vice President Dick Cheney, who said the probe in part "serves as a reminder, if any were need, of why so many Americans have doubts about this Administration's ability to be responsible for our nation's security."
At his confirmation hearings earlier this year, Holder admitted having courted controversy in the past, most notably as deputy attorney general in the last days of the Clinton administration. When Holder helped lawyers for fugitive financier Marc Rich fast track their petition for a pardon, issued by President Clinton after Rich donated significant sums to the Clinton library.
Since taking the reins at Justice, Holder has won plaudits as an exceptional lawyer and able manager. He has, for example, reinvigorated the department's civil rights division, even as he raised eyebrows with some bluntly-stated views on race relations.
In February, he called the U.S. "a nation of cowards" on matters of race, with most Americans avoiding candid discussions of racial issues.
But Holder's most controversial moves have centered on national security. For example, he is leading Obama's drive to close the Guantanamo Bay detention facility by the end of this year.
And he has declassified documents many intelligence veterans think should have remained secret. Now comes Holder's decision on CIA prosecutions -- effectively reversing decisions reached by career prosecutors at Justice in the past.
"I know that this judgment was reached absolutely objectively by them, without any pressure from any of their political 'masters' if you will," said David Rivkin, a Reagan-era Justice Department lawyer. "In effect, what Attorney General Holder has done is basically said that 'I am not satisfied that they did their job well'' and that is actually quite demoralizing to the department."
But for the man Holder has specially appointed to lead the CIA probe -- veteran prosecutor John Durham -- this will be familiar terrain. Durham served the last attorney general, Michael Mukasey in a special investigation of the destruction of CIA videotapes of detainee interrogation.
Rivkin said he suspects that the reason attorneys in the Bush Justice Department did not prosecute the case is because they did not think they could get a jury to convict.
"If you don't have a good reason to think you can get a conviction, you shouldn't prosecute," he said. "I don't think the special prosecutor will be able to get a conviction of a CIA agent. At best, you get someone on perjury or obstruction of justice. Is that really a good thing?"
James Rosen contributed to this report.