One of those Princetonian evangelicals is my buddy, Andy Gill. Andy's one of the only people here with whom I can talk about Francis Chan and Rob Bell... and Andy has a blog... a good blog. You should check it out!
He recently shared some thoughts about "Millennials" and why they're leaving the church. He's got some good things to say! He talks about "the American Jesus" (who I affectionately refer to as 'Merican Jesus) and the Jesus of scripture/history. It's not uncomplicated... I have issues with some of the distinctions he makes, but you should totally check out Andy. He's one of the good guys.
Check out his post on Millennial’s & Church: http://andygill.org/millennials-church/#more-651010