The dirty little secret here that no-one is discussing is that in 1968 nobody got in the National Guard without "special treatment." The connections necessary were not necessarily the high-powered kind that GWB could bring to bear.
But nobody who was of draft age during this period believes you could go down to your local recruiting office and join the Guard. Its a LOL idea.
My not being so much as an idea until after my dad got home from Viet Nam disqualifies me from saying directly that everyone knew that getting into the Guard or Reserves was synonymous with special treatment. I will take it as given that everyone aware in that era knew that for the purposes of this post.
So everyone knew. Everyone, including Dan Rather. Any piece of investigative journalism has to start with a gut feeling that there is a story there prior to finding the proof. For a story about W. getting special treatment into the Guard, that starting point is a no-brainer. The difficult part was that tangible proof was not found until the "memos" showed. They must have seemed to be too-good-to-check. However, if the use of favoritism to enter the Guard was so pervasive, then it would have been dog bites man and not worth a CYA memo.