I would like to be able to use git to clone the issues for various projects on github. I know I can clone the code and the wiki (if it exists). I cannot find a way to clone
It is not possible to clone issues of GitHub repositories. An alternative for you to get the issues' data would be to use the GitHub APIs.
Check out the documentation here to get issues for a repository.
GET /repos/:owner/:repo/issues
You can get the issues' data using the API, store it in file system and then run your necessary scripts on them.