Of course, there are also ornery people with enlightened politics. This raises the question of whether foul progressives and amiable regressives are two versions of the same thing...or whether the similarity between them is merely superficial and does not indicate any deep similarity.
Now the puzzle of how a sweet person can have sour politics and a sour person can have sweet politics is engaging because it brings up considerations about the relative importance of the "personal" and the "political" and the relationship between them.
When we find ourselves facing a puzzle like this, it is often helpful to consider the assumptions we are making about the situation to see if they are giving rise to the puzzle in the first place. Perhaps we are puzzled only because we assume that nice people will have nice politics while those with mean politics will be mean people. Given this assumption, we are troubled when the parallel does not hold.
In simplest terms, the basic idea is that a natural feeling of compassion is biologically hard-wired within each of us. Of course, this seems clearly wrong because if we are hard-wired to be compassionate, then why would there so much cruelty, selfishness, and unnecessary suffering in the world. Here is the explosive part. It turns out that our biologically hard-wired natural capacity to be compassionate can be overridden-by political and religious ideology, especially when it is based in fear. In other words, even though compassion is hard-wired into us and predates culture and experience, we can nevertheless kill and torture one another if we believe strongly enough that doing so is God's will or a way to a better world.
This is explosive because it leads to a complete turnaround of our conventional way of thinking. In The Brothers Karamazov, Dostoevsky has Ivan Karamazov contend that everything is permitted if there is no God. This idea is now widely accepted as a truism. Sartre even claims it is the foundation of existentialism. Interestingly, Leo Strauss, the intellectual father of the neo-conservatives, taught an inversion of this idea-namely, that it is "useful" to encourage common people to believe in God, not because it is true, but because it will help to keep them in line.
The nice person who has a vicious political ideology is an example of this, as is the not so nice person who has a wonderful ideology. Both are acting out of ideology, and so in this sense they are similar. In other words, the social conservative is just like the progressive (both are ideologues), only more so (the social conservative is more dogmatic and less open to revision and experience).
Given this, perhaps the enemy of morality is not atheism but overbearing ideology. If so, then the most powerful wellspring of moral behavior and a movement to a better world would NOT be the ability to stand firmly rooted in one's culture and pick the best available moral ideas (though that is certainly important). It would be an ability to stand apart from one's culture and from all moral ideology in order to reconnect with one's original nature.