Just as a judge should not be ruling on a case where the defendant is throwing suitcases full of money at him, a judge should also not be ruling on a case where the defendant is his own son. Both are inappropriate uses of a power intended for the application of mercy and the correction of faults in the justice system. Both are the sorts of things that should lead to recusal.

Biden's use is far more forgivable, as it's a given that his son was being prosecuted politically to punish Biden (though certainly he was guilty) and would likely have been prosecuted more under Trump, like Comey is being prosecuted today. And certainly "saving your children" is a far more forgivable sin than naked bribery, but being better than Trump is a low bar, but it's still not okay to excuse criminals from punishment because they have an important family member.