There are some things that transend politics. Every president from Thomas Jefferson to Bush has tried to preserve the independence of the executive branch. Presidents believe that congress has no right to their papers or conversations, any more than a president has the rights to congressional conversations or papers. Let congress try to demand communication records from the supreme court if you want to hear a "GO TO HELL" from people in black robes. They would refuse to.
The bigest problem a president has is that he is always surrounded by yes men and woman. Nearly everyone tries to figure out what he wants to hear, then tells him what they think he wants to hear.
Presidents try hard to get people to tell them things they should hear. Often people are told to present views they do not support or believe in. If such presentations ever became public, they would end. Presidents would make a lot more bad decisions than they do.
People will not present all positions on a problem to a president if their is even a slight chance their presentation will be made public.
Thus ever since Thomas Jefferson every president has resisted telling congress about previous presidents deliberations or advice received. For he knows that if he does, the first successor from the other party will pay him back.
Congress has full access to everything a president does. Congress should not have access to what presidential advisors say to the president or to each other. Congress has access to every Supreme court decision. They do not and should not have access to what the justices say to their aids or what the aids say to each other.
Our nation was founded on the principle that anyone can say anything in private. If that does not apply to presidents, it will soon not apply to you.