A law that is not consistently enforced does not serve its purpose  Law without enforcement is not law; it is merely statute -- a promise of law  To institute real law is not merely to declare that such and such behavior is forbidden; it is also to punish those who violate that edict  Furthermore, those who enforce law must punish without favor for their friends or malice for their enemies
To punish only those one dislikes while forgiving others is not to enforce law but to engage in the arbitrary and unjust exercise of power
the unbiased punishment of prohibited behavior