This is one of the little graphics I drew up in class (and made at home on powerpoint) related to what people might expect from the public sphere, and how this might play out (from an overly simplified perspective). Of note, I obviously am not describing the overall structural changes of the public sphere (how public and private law/spheres/opinion get mixed around), nor am I approximating how bureaucratization, corporatization, and organization have changed the structure of our society, and particularly the power structures that influence how the public sphere can influence decisions of policy (being politically empowered).
I simplify things down and give two time periods: 1700 and 2000. In each, I show what people expect of the public sphere and its empowered nature, along with what appears when we examine the actual case. In 2000, I argue that people expect more people to participate in the public spheres (because anyone can, based on larger understandings of citizenship, etc). But the pressures and problems of current institutions and norms force the size/number of public spheres to be smaller, and less powerful, perhaps nonexistent, or disconnected. This gets translated into civic apathy and cynicism because even though people may have the right to vote, speak, and assemble, they don't feel like they have the power to affect change in a way that is meaningful to them.
As always, I don't think that I'm saying all that much interesting, so please comment and critique this view (and my silly little picture).