A President can pardon anything but Treason. Ford pardoned Nixon for anything and everything, without a formal charge, let alone a conviction.
Oh, heck. At first I thought you found the silver bullet. Indict Hillary for treason. But I looked it up and I think you're wrong. From Wikipedia:
In the United States, the pardon power for federal crimes is granted to the President of the United States under Article II, Section 2 of the United States Constitution which states that the President "shall have power to grant reprieves and pardons for offenses against the United States, except in cases of impeachment".
As far as I’m concerned, what Clinton did was treasonous.