This piece grows out of an awareness that the landscape of leadership within the evangelical movement has changed significantly over the last generation. Just as recently as the postwar era of the 1940s and 1950s, it was very easy to gauge whether or not someone was an evangelical by noting how they responded to the name Billy Graham. You knew very clearly what evangelicalism stood for–but not only this, you knew who its leaders were and where they were coming from. They all went to school together, did ministry together, served on the same boards, etc., and as a result they had a very high degree of relational interconnectedness.
But in just a few decades, there has been a massive shift which has resulted in a high degree of disconnectedness within various elements of evangelicalism. Ortberg goes on to cite reasons for this. One is that present-day evangelical leaders are more narrowly niched and come from a greater diversity of backgrounds. Another is that, while in the past evangelicals could identify themselves very easily on the basis of what they were not, but nowadays the landscape has become much more complicated.