Jesus said to give to Caesar what is Caesar's. Today we can legitimately use the metaphor of Empire to categorise the equivalent systems. The dominant capitalism of today is a continuation of Empire, albeit not the specific empire of the Romans. In a way Empire is another way of talking about Kierkegaard's established order. They both demand an ontological significance which is greater than merely social constructions. Empire is the power that wants to be God. It rules us, controls us and demands our subservience.
No wonder that the early Christian writers subverted it by stealing its language. Most famously Paul takes "Caesar is lord" and declares that Jesus is Lord. These kinds of movements are a political statement that identify the church as a political entity. This is a political entity unlike a lobby group or a political party but a political entity which proposes and actualises an alternative sociopolitical reality. Hauerwas is right to suggest that the church does not have a political strategy, it is a political strategy. The simplicity of the acts of faith, the living out of the gospel despite the crushing power of Empire, is the political strategy. Christians are not called to form political parties in order to lobby for justice, we are called to do justice with our own hands. It is somewhat misdirected to make our sole efforts in social justice an appeal to Caesar that he would make Empire more Christ-like. The place for those appeals is after we have given priority to being Christ despite the power of Empire. Even a cursory reading of Jesus' sermon on the mount is enough to tell us this.