Politics always aims at some kind of a harmony or balance of interest, and such a harmony cannot be regarded as directly related to the final harmony of love of the Kingdom of God. All men are naturally inclined to obscure the morally ambiguous element in their political cause by investing it with religious sanctity. This is why religion is more frequently a source of confusion than of light in the political realm. The tendency to equate our political with our Christian convictions causes politics to generate idolatry.
I would like to offer the heretical (for a liberal) suggestion that, for all his wisdom and insight, Niebuhr is no longer relevant to our current political and cultural situation. Indeed, by trying to have it both ways - act out of the love that is the hallmark of the Christian life, yet chiding all those who did so for fooling themselves - relying on Niebuhr as a guide leaves us wondering what possible relevance there is between our faith and political action.
I think the culture wars, in fact, are the best place to show the utter lack of relevance Niebuhr has for our situation today. PD is quite correct further down when he writes the following:
Either a woman has a right to control her own body or an unborn baby has a right to be born. Either gays and lesbians deserve to have their contractual relationships recognized by law or they don't. Basic rights don't admit of much compromise, since our understandings of them are usually grounded in foundational moral principles. Not everything can be reconciled, in short.
These are not just political or cultural (in some kind of broad sense) issues. They are issues that define who we are as a people. Are we people who value the freedom of adult human beings to make decisions about their own lives and bodies, or are we people for whom a fetus trumps such freedom and dignity? Are we people who recognize the reality of same-sex love, and honor it with dignity, or do we enshrine bigotry as part of our refusal to grant equal status to same-sex couples? These are moral questions, and while it might seem easy, even correct, to run to scripture for guidance, we should not stop with specific verses, or passages that might or might not say what we think they say.
This is where the whole question of Niebuhr's relevance becomes clear. Niebuhr was, above all else, a defender of a certain view of the Christian life as transcending the contingent debates and struggles of our common life. By all means we need to be involved in them, he said, but we must not mistake these struggles as having any ultimate meaning or relevance. Except, of course, they do. If they did not, passions would not run as high as they do. We are discussing, at a most basic level, who is and who is not a responsible, equal member of society, to be thought of as having the same intrinsic worth as all others. There is no way to square this circle by saying these are passing issues, to which some kind of religious test, or the whole question of God's love incarnate in our lives and communities have little to say. If the Christian ethic cannot guide us, or if we have to continually remind ourselves that we are not engaged with the whole question of God's love, then of what possible use is it? What possible relevance does the Christian faith have if we have to set its demands aside as we face these difficult issues?