I only wanted to say that the reason we were talking about the distinction between naturalized and naturally born Canadians as dual citizens is that two members of this discussion brought up the issue of oath, and only one category of dual citizenship are oath-takers.
The only other thing I would say is that the history of social contract tradition, which you raised and to which the Supreme Court of Canada is referring, is about a 200-year-long tradition, and with the late exception of Hobbes and possibly Rousseau, all of them agree that the sovereign, the state, does not have the right to expel citizens. The history of social contract tradition is what the Supreme Court is relying on to say that contract is one way: citizens can take themselves out of the state, but states cannot expel their citizens. If you want pages on which Hobbes might have an exception, in which Rousseau does have the exception, I'm happy to provide them to anybody.