Just as people and institutions must not contravene legitimate authority, people in positions of power must not use their authority illegitimately. Moses specifically deals with the case of a king.
He must not acquire many horses for himself…and he must not acquire many wives…also silver and gold he must not acquire in great quantity for himself. When he has taken the throne of his kingdom, he shall have a copy of this law written for him…. It shall remain with him and he shall read it…diligently observing all the words of this law and these statutes. (Deut. 17:16-19)
In this text we see two restrictions on the use of authority—those in authority are not above the law but must obey and uphold it, and those in authority must not abuse their power by enriching themselves.
Today, people in authority may try to put themselves above the law, as for example when police and court workers “fix” traffic tickets for themselves and their friends, or when high-ranking public servants or business employees do not obey the expense policies others are subject to. Similarly, officials may use their power to enrich themselves receiving bribes, zoning, and licensing exemptions, access to privileged information, or personal use of public or private property. Sometimes special perks are granted to those in power as a matter of policy or law, but this does not really eliminate the offense. Moses’ command to kings is not to make sure to get legal authorization for their excesses, but to avoid the excesses altogether. When those in power use their authority not simply to gain special privileges but to create monopolies for their cronies, to appropriate vast lands and assets, and to jail, torture, or kill opponents, the stakes become deadly. There is no difference in kind between petty abuses of power and totalitarian oppression, merely in degree.