here are a couple of things that this brings up (for me) :
1. how relevant is the idea of a social contract to the way that power actually operates today? was it even a good description in the 18th c.?
2. more to the point, I feel like in the original texts (rousseau for example) it's more treated as a kind of thought experiment (the claim isn't that after you make your mark on your birth certificate you also sign another form saying ok sure capitalism sounds great). a lot could be said about this, but do we care about the logical structures of major enlightenment writings? i don't know, I don't think I do, but I could also imagine it becoming interesting...
3. even if you felt that you had entered into a contract, why would you allow that to outweigh, in your mind, the crushing existential problems that it had induced? (I feel like it's almost a given that in this scenario betrayal is usually better than faithfulness).
4. i'm a little put off by how much importance this question (and ones like it) attributes to a possible series of questions that, we are supposed to worry, someone might pose in a debate. It's as if the people asking them are all really anxious to be prepared for thanksgiving with their racist uncles. sure you can have a debate about it, but how does that help you? I feel like the real answer is that if someone says "what about contract theory??" you're better off making a joke, changing the subject, wandering off to refill your glass, really anything other than having a "debate"...