Prosecutors have somehow taken over our country and the lives of all of us are under threat from them. They're grandstanders like Nifong or Spitzer and they decide they don't like you or want to make a point or advance their careers. What happpens? You're toast. They are completely unregulated and unsupervised free agents who make the Grand Inquisitor look like he wasn't really trying.
It all depends on what state you're in. Most career prosecutors understand that they best serve their own career aspirations by best serving the people they represent. I have known many fine ones who take a great deal of pride in their work and in meeting ethical standards.
There are and always have been some dirty prosecutors out there, but Nifong really broke the mold. He's in a class of his own. NC law is such that this could happen again in that state. NC needs major criminal process reform, and they need it now.