The Harvard Political Review has a short article in the current issue titled "Obama's Blank Check," which examines the seeming continuity between the Bush and Obama administrations when it comes to national security. Here's the opening:
In the 2004 Supreme Court decision Hamdi v. Rumsfeld, Justice Sandra Day O’Connor wrote for the plurality: “A state of war is not a blank check for the president when it comes to the rights of the nation’s citizens.” Justice O’Connor’s words marked a turning point in the Bush administration, putting an end to the executive’s unilateral control of American national security policy.
Two years into President Obama’s tenure, however, his administration has come under fire from the left for staying Bush’s course when it comes to national security. These critiques do miss important differences, particularly the fact that President Obama has avoided the sweeping statements of unitary executive power which his predecessor made. But it is nonetheless true that the Obama administration has been defined more by continuity than change in this area of policy.