Obama apparently believed he could avoid what is now happening. In the weeks during which he was weighing the release of the torture memos, there was a vigorous debate within his administration. There was, according to a senior official, considerable support among Obama's advisers for the creation of a 9-11 Commission-style investigation as an alternative to releasing the Justice Department memos. But Obama quashed it.
"His concern was that would ratchet the whole thing up," the official said. "His whole thing is, I banned all this. This chapter is over. What we don't need now is to become a sort of feeding frenzy where we go back and re-litigate all this."
Obama knew he could not stop Congress from doing whatever lawmakers decided to do but he was reluctant to give a presidential imprimatur to a national commission that would keep the controversy alive for months and months and months. Obama had his own agenda and wanted to move on. Putting out the memos was the cleanest way to accomplish his goal.
http://voices.washingtonpost.com/44/2009/04/22/confronting_the_bush_legacy_re.html?wprss=44