They are telling you what they and their clients wish the system was, not what it is. You must not believe what they say. The Constitution and the Supreme Court have done that. It seems that Lessig, a law professor, is probably telling you an accurate description of what the legal system says, while the other lawyers are telling you what it would suit them to believe. Let's argue with them, but not belittle them.
All law is a matter of opinion.
The Constitution is just words on paper, until it's interpreted by the current legal generation and the interpretation changes to suit their views and prejudices. Also, the current legal generation is never a monolith. It is just majority opinions and dissenting opinions. And at this point, there are more of them than of us. I don't think that there is any point in trying to deny that.