While I find the torture recommendations in John Yoo's memos awful, they worry me less than the general assumptions embodied in them about presidential power. After all, the issue of allowable tortures is a narrow issue that can be dealt with efficiently through Congressional legislation, and is almost certainly something to be disavowed by the next administration.
Based on historical precedent, what is less likely to be disavowed by the next administration are the broader definitions of presidential power adopted by GWB. It is in this enhanced theory of presidential power where the real risk to the nation exists, and, unfortunately, there are all too few examples since George Washington's declining to run for office a third time of president's eschewing power. Already, folks on the left are crafting theories around using the imperial presidency to address their favored issues, such as the University of Colorado's proposal for implementing greenhouse gas controls by executive fiat.