Matthew Tuininga being interesting:
The primary problem with southern Presbyterian defenses of segregation was not that they assumed an individualistic view of sin but that they embraced a spiritualized, even neo-platonized understanding of the Gospel. Like their Presbyterian forebear Thornwell, men like Gillespie, Richards and Smith insisted that the spiritual kingdom of God does not take concrete social expression. In other words, their political theology suffered from an under-realized eschatology even more than it did from some sorrt of American individualism.
While this under-realized eschatology led them to conceive of the expression of the kingdom in this life in individualistic terms, it also led them to a greater reliance on the Old Testament as the best source of biblical insight regarding social and political life. Lucas points out that the spirituality of the church doctrine did not lead southern churches to avoid speaking toward political matters; it simply made them selective in the issues that they addressed.
I would make the point more specific by suggesting that the doctrine led them to prioritize the Old Testament over the New Testament as a source for political insight. The Old Testament rendered plausible the theological defense of a thoroughly communitarian and segregated vision of political life, while the rejection of the social and political relevance of the New Testament rendered its more radical and inclusive social ethics moot. Thus southern Presbyterians read Pentecost through Babel, and the unity of the nations in Christ through the division of the nations from Israel, rather than the other way around. Only by interpreting the gospel through the law could they imagine that church membership, let alone justice within political society, could legitimately be constituted on the basis of race.
Read part 2 here. Part 3 has not yet been published.