Er, I think you misunderstood something. Where have I impled that the President is not subject to the law?
The problem is, he's in the unique position of being able to determine what information the police are allowed to have. It's certainly possible for the President to commit a crime. But how would the police investigate such a crime when the President can simply not allow them to do so? How would a case against the President be made when the President can, by himself, effectively quash any search warrant or subpoena?
You have a rather Royal view of presidential authority, but this is not only off topic on this thread but maybe even the forum. It is EvC.