I do think Blair & Bush "massaged" the intel, but I think they thought of it as a white lie. Saddam was sneaky, and the only way to catch him red handed was to go in, so they made the intel seem more sure, when really they were just going on Iraqi dissident, and gut reactions.
Clinton, Albright, Kerry you name it were snookered by Saddam as well. They refused to act on their beliefs that he was making weapons, and they left President Bush to hold the bag.
A conspiracy theorist might even say that Clinton knew Saddam didn't have anything, but dumped bad info on Bush to trick him into over-reaching.