Forgiving one's enemies is a matter of properly identifying one's enemies. An individual who cheers white genocide, for example, does so not because they're our enemy but because they're mind-controlled by our Enemy.
These people are like rabid dogs all of them they are dangerous and must be cured or their power over us otherwise put down but they can not be rightfully called our "enemy."
We forgive them because they don't know what they're doing but we do not forget what they're capable of and we remove their ability to attack us – all without hatred because we're masters of our emotions and this mastery is what separates us from them.
We forgive our "enemies" because we acknowledge they are not our enemies. And when we look into the Abyss and discover who is responsible for turning the people against us and what was is good we find our true Enemy. He is not solely our enemy but the foe of God called Arch-Felon and for such a one there is no forgiveness, not because we are cruel and without reasoning but because he himself is cruel and without reasoning; he, knowing completely what is his error and the consequences does not repent and reform himself but has made (and will always make) the choice to push forward with his evil scheme because inequity was found in him. He is God's enemy and ours. But, should he ever truly repent and God forgive him, so shall we all.
May God rebuke him.