Look, I hate SOPA etc etc, but I think you are going a bit overboard here.
The entertainment industry is a large employer, and the people employed by it are constituents.
You and I may think that SOPA isn't the best way forward, but it is easy to argue that it might protect old, dying industries and the jobs they represent.
Lobby groups are how the voices of people are heard in Washington. It isn't ideal, but nor is it necessarily as corrupt as you are making out.
Also, SOPA is supported by the pharmaceutical and retail industries, which are large employers as well.
The software industry probably employs around 2 million (1.7 million in 2007) .