The point about trying to understand a behavior is to look for a pattern, and to look for the fundamental cause underlying the pattern. You can't see the pattern unless you see the cause. This is induction. The fundamental cause is the one that explains the most characteristics of the pattern. To ask for "more evidence" is to miss the point.
In my opinion, Straussian Platonism (SP) is indeed what governs the Bush administration. Not until I read Dr. Lewis' article did I grasp the nature of the pattern! If you want to answer Dr. Lewis' central thesis, you have to address it directly. Do you agree that SP exists? If so, the oweness is on you to show the more fundamental cause. How is "pragmatism" more fundamental than Straussian Platonism?