This New York Times article sympathetically conveys the argument that because their staff could not be briefed, “few lawmakers are equipped to make difficult legal and policy judgments about secret programs.” My experience with highly classified programs such as this is that even within the executive branch, few officials at the staff level outside of the intelligence community are given access to this information, so you probably could make the argument that the policymakers were at the same disadvantage as members of Congress, having to rely on a handful of lawyers at OLC for legal opinions. Also, how ridiculous is Pelosi’s statement that she recalls being briefed but that she didn’t think the methods would be used?
In addition, former Senator Bob Graham, who famously keeps a journal about every detail of his life can’t remember whether he was ever briefed.