I am responding to some discussion in Spare Oom on Lewis and the Religious Right.
I think that Lewis's thought does reflect the acceptance of certain principles which are held dear by political conservatives. At the same time, terms like "conservativsm" and "liberalism" shift meaning from generation to generation. For example, is George W. Bush a real advocate of balanced budgets and limited government? Is nation-building in something that Barry Goldwater would approve of, if he were still alive? In the present day very often "conservatism" ends up being a matter of doing whatever benefits the big corporations, something I am sure Lewis would not support.
In the C. S. Lewis encyclopedia edited by John West and Jeffrey Schultz West has an entry on Lewis and political conservatism in which he point out a number of conservative prinicples Lewis defended but then pointed out that Lewis supported to system of socialized medicine in Britain! (Hillary take note).
Of course the term "Religious Right" is a highly loaded term which stands in need of definition. The attempt to ally Christianity with any political party or movement, however, is something Lewis criticizes devastatingly in his essay "Meditation on the Third Commandment." In fact, I consider that essay to be a pre-emptive demolition of the pretensions of the Moral Majority and its successors. I don't consider the idea that we need to enlist the government to defend the family to be an especially conservative idea, or an especially good idea either.
In short, there is a serious question to be asked as to what "conservatism" means. Once we clarify it, we will find that Lewis supports some but not all conservative principles. But the attempt to ally the fortunes of the Gospel with the fortunes of any political party or movement is something that Lewis condemned on no uncertain terms.