If I am reading this correctly, you want to maintain multiple versions of the same blog post, correct? This isn't really 'version control' (git, svn, etc...) in the traditional sense .

At a high level, you could just keep a record of every version of every blog post, then separately maintain which entry is most current, or active, or whatever metric you want to display/query. This will let you maintain all versions of the blog post and you can run diffs on different versions, revert to older versions and branch from any version.