Then surely the Lib Dems should be winning Kensington and Chelsea?
Fair point, although Kensington and Chelsea would probably be significantly different (though no less affluent) than places like Richmond Park and Twickenham that are both very affluent and also pretty liberal in their politics (potentially fertile ground for a Cameron led Conservative Party)... however it's worth making the distinction (as Al does) that Sutton and Chelms is less affluent, and also a good deal more marginal politically (in fact the Sutton seats are both very marginal and IMHO very vulnerable).