Check out the lecture "Lutheran Identity in America" here:
The most interesting aspect of Mainline Protestantism in America was that the odd situation in the Mainline Protestant Churches. Here's what it is:
This sociologist of Religion (whose name escapes me) wrote a book back in the 60s claiming that there were going to be some major fights in the Mainline Churches in the coming decades over politics. He claimed this because in survey after survey it was found that Mainline Protestant clergy are overwhelming liberal and their congregations are overwhelmingly moderate/conservative.
This didn't really happen with regard to politics (perhaps with other things). That's mainly because if parishners didn't like the politics of their minister they would generally just leave. Hence the demographic decline of the Mainline.
I totally get this. I held out in the ELCA as long as I could (that is as long as conscience would permit). And what most annoyed me was the fact that week-after-week it was some sort of political message that I didn't agree with. I'm a political conservative (though I don't intend to talk about it much on this blog, because I'm interested in discussing theology here and I think it's very dangerous to equate a particular political commitment directly with Christianity) and so I got tired of hearing politically liberal messages when I wanted to hear about the faith. Of course most of them directly identified the message of the political left with Christianity, something I had deep problems with. I'm equally uncomfortable saying Jesus stands for Capitalism and limited government, even if I think those things are good.
Now, maybe the Mainline could get the message and knock it off. Unfortunately for them, the reason why they do this is because if they did they wouldn't have anything to talk about. Frankly, a great deal of them believe that non-Christians aren't going to hell and that pretty much no one goes to hell. So, if you're not saving people from hell, what are you doing?
Basically, to put it bluntly, they've got to come up with something to talk about. They've also got to come up with a point to Christianity. Because if it's not about get people out of eternal perdition, what's it about?