A federal judge might try to block the public release but it won't work. POTUS is THE Classification Authority for the United States of America. ALL other classification authorities derive their statutory authority from him.
Documents are classified so as to protect information, the release of which would be damaging to the national interest. The level of classification, and hence the protective measures taken, is directly related to nature of the information.
If the President decides something, anything, should be declassified and published then, ipso facto, it is. Period. There is NO RECOURSE to the courts.
That said, I seriously doubt there is anything in the memo that is otherwise classified. The memo is a summary of the findings of the House Intel Committee. Anything classified would be found in various appendices which would be individually classified depending on the nature and source of the information. It is important to note that it is the information which makes a document classified and NOT the markings on the document. This is why Hillary committed felony when she sent and received emails containing classified information regardless of the presence or absence of required markings.
"Ceterum censeo Islam esse delendam."
Garde la Foi, mes amis! Nous nous sommes les sauveurs de la République! Maintenant et Toujours!
(Keep the Faith, my friends! We are the saviors of the Republic! Now and Forever!)
LonePalm, le Républicain du verre cassé (The Broken Glass Republican)
You keep ignoring the fact that they already released it to Justice.