The Mother Of All Credibility Gaps

Is there no principle subject to negotiation? Is there no course subject to reversal? For the Bush administration to argue for years that this program, as operated, was critical to our national security and fell within the president's Constitutional authority, to then turnaround and surrender presidential authority this way is disgraceful. The administration is repudiating all the arguments it has made in testimony, legal briefs, and public statements. This goes to the heart of the White House's credibility. How can it cast away such a fundamental position of principle and law like this?