Huggy Behr in The Guardian asks what ideological legacy Cameron will leave. Daft question. Cameron is a public relations man not a political thinker. PR men leave smudges, some of them on underpants, not ideas or policies.
Cameron's basic principle is the survival of Cameron. To ensure that he's happy to chuck overboard everything he once appeared to support but really didn't. So hug a hoodie becomes ‘hit their benefits’. Hug a huskie becomes green crap. Euro enthusiasm becomes flirting with Brexit. No top down reorganisation of the NHS becomes the biggest ever. And so it goes on, but don't assume that the new principles are Cam's real views either. Like his earlier effusions they'll all change again if necessary, because the basic rule in political PR is "Here are my principles. If you don't like them I'll change them".
Perhaps it's better now to change the man than have him find another set of principles.