Houston, we have a problem. There is no specific definition for that phrase. That's why it is so useful in the vernacular.
The problem with discussing the phrase “moral high ground” is that the phrase is an idiom. Idioms have no literal definition.
That’s why I gave it a definition in the context I used it: turn the other cheek. Oops. That is another idiom. Boy, I like those things!
Now, what I mean by that is: if you don’t like something then disengage it -- the passive response inferred in 'turning the other cheek' -- otherwise, you run the risk of becoming just like it. Disengagement is not an idiom, so now everybody should know what I really mean without any confusion.
That's what my mother always told me to do: if you don't like somebody, stay away from them.