That's the thing: so much of modern conservatism is just cargo-cult thinking. Lower taxes (esp. wrt the mythical Laffer Curve which is making a comeback now), deregulation, market economies as an intrinsic good as opposed to a tool (which conveniently shields them from criticism). And so on. And that's just on the economics side.
If you operate according to the maxim "that government is best which governs least" the logical conclusion of that is "that government is best which governs not at all", which is basically what we're getting from conservative politics these days.