At this point I remind myself that I am not designing a system of governance from scratch. Almost everyone--if not everyone--in this room is an American. We have a Constitution that presents us with a law with which I must begin if I am a Christian ruler in America.
Here God models a first insight for us--He starts with people where they are and works to bring them of their own "free will" to where He wants them to be. The very nature of biblical revelation thrusts this conclusion on us time and time again. Each book reflects the language and paradigms of its own time and place, from the stars in between the waters in Genesis 1 to the three heavens of Paul.
Thankfully, there is a great deal of overlap between America's laws and Christian values. Our Constitution is a social contract meant to protect the rights of all within its boundaries. It thus in theory is wired against the harm of anyone.
In my opinion, when we can show that certain actions harm others, we can work within the system to outlaw them. At times our culture has a blind spot to such harm. Slavery would be one instance. The refusal to give voice to women was another. We might look to abortion and racial discrimination as two instances that we are currently working on today. These are areas in which the law still allows individuals to do harm to others.
I believe a Christian ruler would work as wise as a serpent within our society to make it as harmless as a dove toward the unborn and toward those many others disempowered in it. By this comment I mean that some paths to these ends are more effective than others. For example, shooting abortion doctors hardly reduces the number of abortions or brings its legal end any closer.
I believe a Christian rulers would work within the American system for the benefit of all. While the Constitution really works more against the detriment of all than for the benefit of all, this is a small step our system allows.
A Christian ruler would thus make a priority the empowerment of the oppressed or downtrodden. I cannot believe that a Christian ruler would not make it a priority to educate and transform those who are in a perpetual cycle of disempowerment in society. While it is true that such cycles are often a product of choices, they are not empowered choices. How could it not be Christian to help others from the slavery of their environment?
God does not insist that people choose Him. But He seeks to influence others for Him. A ruler who would write off or simply abandon some segment of society, without seeking to woo it to the better, is not worthy to have Christ's name in front of him or her.