I think Gerry McDermott has made some valuable points on the state of American "evangelicalism" today. He says there are two groups: Traditionalists and Meliorists, and it all goes back to their view of Scripture as authoritative. Here are some of his insights...
The logic of the Meliorist approach would lead evangelicalism to follow the path of mainline Protestantism over the last decades, as it continued to proclaim the authority of Scripture and respect for tradition while rejecting the Tradition (and in particular its reading of Scripture) at precisely the points where the culture was at war with biblical teaching. In moral theology, for example, if the words of Scripture are culture-bound and not inspired, the particulars of Levitical or Pauline sexual admonitions must give way to the true Word behind the words—love and non-judgmentalism—when confronted by the experience of committed love and presumed new knowledge.
For most Meliorists, the Bible’s authority is primarily functional. But Vanhoozer insists that Scripture has ontological authority. God uses the words of Scripture to speak to us, but the giving of the canon itself is a divine act speaking to the world. The Spirit is active not only on those occasions when particular parts of the Bible are illuminated for us, but was also already active in the formation of the words of the canon.
In these ways and others, Vanhoozer shows in a post-foundationalist way that experience and doctrine are intrinsically tied up in one another, and that the Bible’s words (not just concepts) are given by God just as He gives them afresh every time they are read or preached. The Meliorists’ exaltation of experience over doctrine is a false dichotomy, and their dissociation of revelation from biblical words slights God’s work of revelation in history.
Meliorists say the historic Church’s understanding of Scripture should be closely scrutinized. Some of them profess respect for the Great Tradition, but because of their slippery approach to biblical inspiration and subordination of doctrine to experience, their relation to that Tradition is tenuous. Because the meaning of the Word is found not in the words of the Bible but in the theology of the Meliorist interpreter, sola scriptura can become—despite the best intentions of its leading thinkers— sola theologia, with the charismatic theologian the final authority.