One of the reasons that the ELCA is so extremely liberal is the inclusion of former LCMS “progressive” dissidents. The most radical of the ELCA predecessor bodies was the AELC, which had split off from the LCMS following Seminex. Thanks to a constitutional quota system, the AELC contingent had disproportionate influence in the ELCA’s policies which set the Synod on a direct course for the shoals it now finds itself on.
I’m not so sure that the AELC added that much more radicalism. The former LCA was just as radical and 30 times larger - at least on paper.
On the other hand, the impetus that led the Seminex crowd out of the LC-MS to form the AELC was the best ecclesiastical enema the Lutheran church ever received.
“Gospel Reductionism” = Seminex deceptionism.