How much broader can it get? The President can literally pardon any person for any federal crime for any reason. The only exception to that is impeachment. What he can't do is pardon for state crimes.
“What he can’t do is pardon for state crimes.”
That is true, but has never been directly determined by the Supreme Court.
We may soon arrive at a point in the current constitution crisis, that would be ongoing coup against the president, where that question should be answered.
Pardon for a state indictment or conviction and take to the Supreme Court.