There used to be a lively Christian left in America which while not quite yet extinct is teetering on the edge of the abyss. Like pandas they don’t show much interest in breeding and their main hope for survival is zoos, I mean, university theology departments. I don’t say this with any gloating, the Christian right to which I am more sympathetic will likely cease to exist as a meaningful movement in the next ten years or so. Once you become so caught up in politics that you equate being a good Christian with being a good member of a political party, there is no reason to stay Christian.
The Christian left succumbed first because of an internal problem, the constant tendency to equate the Kingdom of God with the Kingdom of Man.
Jesus commands his followers to preach the Gospel to all men, to heal the sick, to cast out demons, and to feed the poor. For about nineteen centuries these were taken as commands to the church, that is to the body of believers, which each individual believer was to fulfill in a manner fitting his possibilities and vocation. The Christian progressive however sees this command as being issued to the state. Of course he doesn’t want the state to preach the Gospel or cast out demons, that wouldn’t be progressive, but he does think the state should obey Jesus’ commands by providing universal healthcare.
In the Gospels Jesus does not speak about how the world is to be organised. His attitude towards politicians ranged from annoyed indifference (Herod the Tetrarch) to outright hostility (the Sadducees). According to John’s Gospel he preached to Pilate but didn’t mention social justice. In the Synoptics he doesn’t bother to say anything to Pilate. The Gospel descriptions of Pilate are classic portraits of the political type: his advanced calculus of the dynamics of power does not change the fact he is impotent. His power is an illusion, but to hang onto the illusion he condemns a good man to death.
St Paul was a patriotic Roman citizen but the extent of his political theology was seeing political figures as exercising the providential role of punishing evildoers (i.e. hanging brigands and the such) but otherwise hoping they would leave the church alone.
We should not jump too quickly however to the conclusion that Jesus and his earliest followers had no political interest, if only for the simple fact that the sharp distinction between politics and religion is a modern one. While Jesus displayed little interest in those who occupied office or in how the state worked, and while he drew a revolutionary distinction between the sacred and secular spheres (render unto Caesar what is Caesar’s, and to God what is God’s) the way of life he preaches is not a religion of the heart promising individual salvation with no effect on the surrounding world.
Jesus was an eschatological prophet who preached the end of one era and the beginning of a new one. If we put aside dogmatic theology and look at the matter from the perspective of history, Jesus appears as a man who well ahead of his peers grasped that the trajectory of Israel was towards utter disaster and that the politicians who seemed to be in charge of the situation were in fact powerless to avert the disaster. In this he was much like Jeremiah, but unlike Jeremiah he does not propose a return to God within the bounds of what we now all Judaism. For Jesus the solution was for Israel to reconstitute itself, which is why among his prophetic acts he included setting up rules of life, establishing new rituals, and even an embryonic structure for a new community.
It is impossible to say what Jesus imagined his community would look like in the years after his death, and he issued no political program to his followers, but you do not found a new society if you do not want to change society. He claimed he was establishing the Kingdom of God, that is, the space where God is king and where his law is followed. This Kingdom could not help but be transformative.