A missing element in the discussion may be this: Different ideas about the work of the Holy Spirit.
Among conservative Lutherans, the emphasis is on the work of the Spirit in and through God's Word. Other Lutherans, however, will maintain some work of the Spirit unrestricted by God's Word. That opens up the possibility that the Spirit is leading in new ways. This is precisely how some Baptists and Pentecostals arrived at women's ordination. Sort of, "If the Spirit is blessing and moving in that direction, so should we." They then tend to reconcile the changes with potentially restrictive passages in new ways.
As I read statements from Charles/ELCA, I'm seeing something similar with respect to ordaining homosexuals. There is belief that the Spirit is moving the church in this new direction. I'll let Charles decide whether I've stated this with his understanding.
I would invite someone from NALC to comment on how this is or isn't working in their church body, which sees the ELCA as going too far.
One speaker I heard took a still different approach. According to him, it was/is an issue of applying our core doctrine of justification by God's grace to a new situation - life-long same-sex partnerships. What does it mean for us to proclaiming salvation by grace when talking about (or to) a homosexual who has found a life-partner in someone of the same sex?
Another thought from reading Peter's first post.
If our doctrine is true, it's truth should be seen in the lives of real people. A question I have on my biblical study sheet (after I've done all the Greek exegetical stuff and come to an interpretation of the text): "How has the biblical truth been re-enacted in my life or in the life of someone I know?" If a doctrinal truth is not being enacted in the lives of real people, it's just a theory, or, at worst, a lie. Another way I've phrased this (borrowed from a book by an Episcopal laywoman: "The real question is not: "What do you believe?", but "What difference does it make in your life that you believe?" The real issue is not our doctrines, but how they make a difference in people's lives. At least in my opinion, if the doctrines make people more judgmental, more hateful, more sectarian, rather than more loving and Christlike, and supportive of the "least of these," then maybe they need to be re-evaluated.