Much as I'm loathe to admit it, Obama was right when he pulled back the curtain and talked about The Blob as being the immense American government apparatus that will always prevent actual change. I doubt Obama would have made big changes, but he did talk about how anything that went against the Blob, in this particular case I think he was talking about universal healthcare, would be shut down by all sides

I think you're right in that Bernie would absolutely have been limited by the apparatus around him, no matter how much he tried to change it