A reader writes:
In response to a reader, you say,
"The Republicans had become so enthralled by what they were against that they had forgotten what they were supposed to be for."
In a broader context, isn't this the crux of Fundamentalism? While the faithful can simply say, "This is what I believe," a Fundamentalist must say "This is what I believe, and what you believe is wrong." A Fundamentalist defines himself by what he is not.
This is also a good working definition of original sin. At the beginning of his Ethics, Dietrich Bonhoeffer wrote (I'm grossly paraphrasing here) that before the Fall, man was aware only of God, and had no awareness of himself apart from God, as one who looks straight into the sun cannot see anything but the sun. The Fall came when man turned away from God and became aware of himself as something apart from God, as one who turns from the sun and sees his shadow is aware of himself only as an absence of light.
In the Old Testament, this is illustrated by Jonah, who (unsuccessfully) fled from God when commanded to go to Nineveh. In the New Testament, the parable of the pharisee and the publican makes the same point.
Seeing yourself only as what you are, rather than as what you are not, requires Christ-like humility. All who try will fail. The Fundamentalist embraces this failing and proclaims it as virtue. This is why Fundamentalist religion and Fundamentalist nationalism (jingoist patriotism) are such natural allies.
Christianity can and will survive the fundamentalist temptation. It ahs in the past; and it will in the future. It's just the recognition of a lost spiritual compass that is hard.