In case you have not seen any of the (deserved) zillion other references to this at various Atlantic sites, it is very much worth reading my colleague Joshua Green's new story about what went wrong with Hillary Clinton's campaign, and the trove of memos he collected while reporting the story.
Josh has done an outstanding job on this beat for a long time, starting with his definitive article nearly two years ago about how Hillary Clinton's success in the Senate had prepared her, and perhaps mis-positioned her, for a run for the presidency. Also, as everyone in media-land knows, a year ago GQ commissioned him for a big piece on the Clinton campaign -- which the magazine then killed, by all accounts as part of a deal to get better access to Bill Clinton for a different story. Josh then published this excellent account instead in the Atlantic.
The magnum opus among the memos, based on what I've seen, is this one from Mark Penn, which is sure to be parsed and reflected-upon for months and years.
Related thought that comes to my mind while reading through these documents: I make my living writing things down, but even I have reached the point where I am not willing to put any sentiment whatsoever into reproducible form -- in an email that could be forwarded, in a document that could be cut-and-pasted -- without thinking about how it would look if it got into unintended hands.
That is, the perfection of the technology for spreading and sharing written material has made writing weirdly less useful for conveying private thought. It's risky as a way to share thoughts about running a political campaign; it's reckless as a way to say anything about any other person you might not want him or her to hear. The evolution of technology may return us to the era when the no-tech face-to-face meeting, or the hard-to-copy handwritten note, is the most secure means of communication. And when written statements, even in the "privacy" of email, are necessarily blanded-down by pre-knowledge that they could turn up somewhere unexpected months or years or decades later.