(Enough to make one) turn in one's grave is an idiom to describe an extreme level of shock or an intense level of
surprise, and is expressed as the vicarious sentiment of a deceased person. This hyperbolic figure of speech is used to describe the upset,
disgust, horror or anger of a
deceased person if he or she were alive to hear of a certain news story, action or idea – especially a negative one. It is also said of the deceased founder(s) of governments or private institutions if their extant leadership goes against the founder(s)' principles or pursue(s) programs that the founder(s) would not have executed or envisioned. The main idea is that instead of being able to rest in peace, the dead person in question is sleeping uncomfortably, akin to the uncomfortable and irritating "rolling around in one's bed" action when one cannot
sleep. The phrase dates from the mid- to late-nineteenth century.