Are Special Interest Groups Weakening?

Are special interests now weakening? Here's a Jonathan Rauch review of a new book by Gunnar Trumbull about exactly that. Previous I'd written about the problem of increasing specialization for commerce and individual decision-making; really that's just Manicur Olson's special interest sclerosis problem, as it directly affects the lives and commerce of individuals rather than specifically the political process.

Cross-posted at my church-state separation blog.