You don’t just “fix the pardoning problem.” It’s defined in the Constitution (emphasis mine):
The President shall be Commander in Chief of the Army and Navy of the United States, and of the Militia of the several States, when called into the actual Service of the United States; he may require the Opinion, in writing, of the principal Officer in each of the executive Departments, upon any Subject relating to the Duties of their respective Offices, and he shall have Power to grant Reprieves and Pardons for Offences against the United States, except in Cases of Impeachment.
That’s literally all it says with regard to pardons so there’s plenty of wiggle room here. As one could imagine changing the Constitution isn’t exactly a walk in the park.
There’s a non zero chance of a constitutional crisis bring triggered here depending on what happens as a result of this investigation.
