What's an intuitive derivation behind ODO's definition that helps to internalise its meaning:
to patriate = Transfer control over (a constitution) from a mother country to its former dependency:
Etymonline: 1966, in Canadian English (perhaps coined by Lester B. Pearson) in reference to constitutional laws, probably a back-formation from repatriate.
Wikipedia: The word "patriation" was invented in Canada as a back-formation from "repatriation" (returning to one's country). As the Canadian constitution was originally a British law, it could not "return to" Canada.
So I know that this is a Canadian term, but what's the relationship between it could not "return to" Canada and the elimination of the prefix 're'? How's this word a 'back-formation'?