I think there’s a category of “secret” that is relevant now (and has been in the past with previous Presidents).
Presumably PotUS isn’t allowed to obtain information about some investigations being carried out by the Dept. of Justice, esp. the details of a Special Prosecutor investigating said PotUS.
In the current case, I don’t think Donald J. Trump will get anywhere if he demands that Mueller turn over copies of everything they’ve collected.
Not sure how far this limit would go. Surely there must be some law in effect to prevent PotUS from getting copies of files of a lot of other case files.
Tax information on other people as well as raw info from recent censuses are also presumably protected from casual inquires by PotUS.
But going by the OP, are these “state secrets”? We could also say the President cannot get a hold of HIPPA or FERPA information but does that really answer the question?
Tax records are not classified state secrets. Access is controlled by statute in order to protect the privacy of citizens. That’s a different ballgame from what the OP is talking about.
26 USC § 6103 - Confidentiality and disclosure of returns and return information
Perhaps an argument can be made that Presidential authority to know all military information, and foreign intel, could be said to derive from Art II grants of power — but I don’t see any nexus for the claim that income tax would fit. Congress has that authority.
Its not a direct answer but my understanding is Truman was in the dark about the Manhattan project until he became president and took over for FDR. So I guess there are some secrets that are kept from the VP.