His piece "Christianity in Crisis" describes the awful corruption of Christianity that we now see in what he calls "Christianism" -- intertwining of Christian institutions's with radical rightwing politics: he hold "Christian conservatism" to be neither.
He starts out by invoking Thomas Jefferson, who described himself as a "real Christian, a disciples of the doctrines of Jesus", but Sullivan's model for the alternative Christianity is actually St. Francis.
As Jesus was without politics, so was Francis. As Jesus fled from crowds, so did Francis—often to bare shacks in woodlands, to pray and be with God and nature. It’s critical to recall that he did not do this in rebellion against orthodoxy or even church authority. He obeyed orders from bishops and even the pope himself. His main obsession wasn’t nature, which came to sublime fruition in his final “Canticle of the Sun,” but the cleanliness of the cloths, chalices, and ornaments surrounding the holy eucharist.
His revulsion at even the hint of comfort or wealth could be extreme. As he lay dying and was offered a pillow to rest on, he slept through the night only to wake the next day in a rage, hitting the monk who had given him the pillow and recoiling in disgust at his own weakness in accepting its balm. One of his few commands was that his brothers never ride a horse; they had to walk or ride a donkey. What inspired his fellow Christians to rebuild and reform the church in his day was simply his own example of humility, service, and sanctity.
A modern person would see such a man as crazy, and there were many at the time who thought so too. He sang sermons in the streets, sometimes just miming them. He suffered intense bouts of doubt, self-loathing, and depression. He had visions. You could have diagnosed his postwar conversion as an outgrowth of posttraumatic-stress disorder. Or you can simply observe what those around him testified to: something special, unique, mysterious, holy. To reduce one’s life to essentials, to ask merely for daily bread, forgiveness of others, and denial of self is, in many ways, a form of madness. It is also a form of liberation. It lets go of complexity and focuses on simplicity. Francis did not found an order designed to think or control. He insisted on the simplicity of manual labor, prayer, and the sacraments. That was enough for him.
Andrew Sullivan has surprised us often, but I have a hard time imagining that he is about to take up the begging bowl and try to be the lesser brother who whispers his thoughts into the ears of others, so as to not exercise too much power. So, his vision of a resurrected Christianity is off-kilter; it's a fantasy life for him.
What he does not hold out as a hope is a politically engaged, empowering, inclusive, decentralized, religious institution that supports and enables personal spiritual development.
Sullivan is a Catholic, and so he seems to see his only choice as the hierarchy or the mendicant monk. He doesn't quite get Protestantism as a viable reform movement in Christianity, especially the fruits of the Radical Reformation, which persist today in the radically inclusive sects like Quakerism and the Unitarian Universalism I serve, and which influenced Jefferson.
Sullivan starts with Jefferson's Bible, but does not follow that historical thread. Jefferson had contemporaries and together they all have heirs, in that many others have pursued the project of an institutionalized "pure Christianity."