I know Zinni a little bit. He's reflective of many of the General grade officers I have known - not exceptionally political, and they base their opinions on practical experience and history, rather than a political orthodoxy. Frequently, they find themselves at odds with both parties.
If you read Zinni's autobiography - the one that was written with Tom Clancy - many of his criticisms of the 2003 Iraq invasion of very valid.
And, you may or may not remember, but Zinni enthusiastically supported the troop surge in 2007 - something that didn't get nearly as much publicity as his opposition to Rumsfeld's war planning. You may also remember that Hilary and Bill (and Obama) were all against the surge - placing them at odds with Zinni. I don't think Zinni is anyone's shill.
Some of that I remember and some of it I don’t....but wasn’t Zinni an advisor to Hillary Clinton after he retired?