This is a very good essay about Why Conservatives Can't Govern.
But it's hard to imagine how any essay of modern conservatism can fail to account for the disproportionate role played in it by the Christian Right.
At first glance the religious component of American conservativism might not seem all that important when trying to understand the scandals, hubris and debacles generated by the first Republican Presidency and Republican Congress in over fifty years. Nevertheless, the GOP's radical Christian base has made its elections--and therefore its bad governance--possible. Just as importantly, it has also either directly or indirectly helped to thwart any attempts to make the Republican regime accountable. Conservative Christians have contributed passionate voices and messianic themes to a conservatism already suffering from delusions of grandeur and have been an important, if somewhat under-recognized influence on and defense of, the Administration's unchecked foreign policy theories and actions, especially and obviously as it concerns the war against and occupation of Iraq.
At the same time, the GOP's Christian conservative base has either stayed silent on such matters as bankruptcy "reform", tort "reform", budget-busting and income inequality increasing tax cuts, fund-raising and lobbying scandals in Congress and in the executive branch, Katrina, Guatanamo and rendition, NSA spying, and the war, or has supported or defended the administration in each case, excusing unjust, corrupt or incompetent policies (and just as importantly, the ruthless politics that enables those policies).
In short, ruling conservatism's inability to govern stemming from its ideological predispositions is highly related to, if not directly driven by, its ties to fundamentalist Christianity, and the latter's otherworldy conceptions of evidence, analysis and logic. It isn't just that conservatism's free market apostles skew the party's ability to support the institutions its elections have made them responsible for, but also that this quasi-free market ideology is closely intertwined with a religious system of belief that is hostile to the most basic assumptions of science, testing and learning, which are necessary for governments to function at even a basic level.