I was just tracking some information down on John Conyers, who chairs the House Judiciary Committee, and ran across this report from March 2009 on accusations that the Bush Administration's use of executive power bordered on the imperial. Its quite partisan, but introduces the concept of the Imperial Presidency, which my 2302s study when we cover the executive.
For what its worth, there are allegations that Obama has picked up where Bush-Cheney left off with similar abuses. Glenn Greenwald at Salon beats this drum quite a bit. Power once acquired is difficult to relinquish.
