Jack Danforth once stood at the intersection of religion and politics. He was a moderate Re-publican, three-term senator, diplomat. He is also an Episcopal priest, so pious that his Senate colleagues called him “St. Jack.” With his new book “Faith and Politics,” in stores next week, Danforth–now 70 and retired–positions himself as an outsider. He takes his own beloved party to task for allowing itself to be hijacked by the Christian right.