Concerning Christians praying for coporate forgiveness of national sins, 
Michael Covington claims the following of C.S. Lewis:

<><

I was surprised when I heard this same kind of remark from a fellow grad. 
student I know, especially since he had seminary training.  I have read the 
same essay and do not find Lewis making any such claim.  Rather, Lewis is 
condemning the use of such coporate prayer efforts as platforms to make 
political jabs at opponents, feigned as confessions of guilt (ie., Lord please 
forgive us for allowing "insert political issue/idea/platform" to exist in our
country, it is wrong and we ask your forgiveness.).  I would be interested in
knowing what part of the essay you feel condemns national repentance (please
quote).