Kathleen Parker has an article about the Democrat's new strategy of exploiting God for political purposes. This is bad news for the Church. When it becomes politically expedient to call yourself a Christian, it creates an incentive for the most ambitious and ruthless people to worm their way into the Church under false pretenses.
Of course there always have been and always will be birds (evil people) nesting in the branches of the great mustard shrub/tree that is the Church, but under normal circumstances the harm they can do is limited. But when the Church becomes a source of political power, the damage that can be done grows enormously.
This, incidentally, is one of the reasons that evangelicals oppose large church hierarchies --they create political power centers that will naturally be coveted by unbelievers. They create an incentive for unbelievers to become counterfeit believers.
Secularists have accused "Christians" of all sorts of evil: the Crusades, the Inquisitions, inter-Christian religious wars, Nazism, the Oklahoma City bombings, and others. Nearly all of the accusations about events after the enlightenment are historically ignorant or otherwise mistaken. But accusations about earlier events have some merit.
Some of these earlier events have been twisted by the prosecution. The Crusades, for example, were a defensive war against a dangerous religious movement that fully intended to wipe out Christianity. Many people don't realize that most of the Middle East and Mediterranean were Christian at one time and that they were violently converted by Muslim armies. The Muslims had no intention of stopping at Turkey, and if Europe had not gathered together to fight back, the Muslims would likely have conquered all of Europe, piece by piece. Yes, there were atrocities, committed, but nothing that was uncommon for warfare in that day and age.
But that still leaves the inter-Christian wars and the Inquisitions. Both of these are enormous stains on the honor of the Church. And both of them happened because the Church was politically significant, a source of power and prestige that was coveted by ambitious men.
If there had been no incentive for ambitious men to join the Church and seek promotion within its ranks then these things wouldn't have happened --or wouldn't have involved the Church. If the only powers of the Church were to grow believers and to spread the Word, then the only men seeking Church leadership would have been men who were ambitious to do God's will.
UPDATE: La Shawn has some comments on the Democrat's new strategy too, and she quotes something from David Limbaugh on the subject. So far I haven't seen anyone else worried about the influence of power though...