Nice work @ats-david! Some additional problems with social contract theory.

The social contract is substituted for the Constitution in legal philosophy. The Constitution derives it power from 'the people', the collective metaphysical monstrosity that is the nation. But, the multitude of individuals cannot be called a nation before they unite behind a social contract. Rousseau says that the social contract transforms 'the multitude' of individuals into a nation with a general will. The founding act of the nation is writing and signing the Constitution in name of the people in the nation. Conclusion: the general will [the nation] is the foundation of the constitution, but it is the constitution that creates a nation out of the multitude of individuals. How can you authorize yourself into existence? That is the first problem with constitutional theory.
The second problem is much greater, and also links to Rousseau. If it is true that the state is comprised of free and equal individuals, how does it at the same time have the power to dominate over those free and equal individuals? There is an inherent tension between 'free and equal' and 'monopoly on force'.

This doesn't even touch upon the reification of 'the people', 'the nation', 'general will' and more of that nonsense, which is another giant problem with social contract theory. In trying to be an alternative to divine right of kings, it comes up with an even shoddier metaphysics. Which, when you think about it, is really impressive, actually.
~Andrea