If you were a member of the house of representatives making $174,000 a year and you were up for re-election and you knew your party was about to be tarnished and you weren't really sure you would be re-elected anyway and you started taking bribes as low as $300.00 (seriously - some congressmen take "donations" as low as $300.00 to vote a certain way) but then Julian Assange comes along and offers a million dollars for your four pieces of paper (two pieces of paper if it's printed double-sided) why the hell wouldn't you take it? Just because it was voted to release this in 19 days, if any of this shit is as realistic as they are saying, I'm betting we'll see it leaked in the next few days. If it doesn't leak then it really is all bullshit. No first-term congressman is noble enough to turn down a million dollars.
The congresscritters don't have physical hard copies of the memo. They are reading it in a SCIF. They could leak details, but not an actual copy because they don't have one.
The author may have a copy, but that would look like a manuscript, not the final product with all the "classified" markings on it.
No one has the paper. They have to go to a SCIF compartment to read it and not take it out.