Full Idea
Social contract theory ...satisfies the twin demands of universalism - every person must be obligated - and voluntarism - political obligations can come into existence only through consent.
Gist of Idea
Social contract theory has the attracton of including everyone, and being voluntary
Source
Jonathan Wolff (An Introduction to Political Philosophy (Rev) [2006], 2 'Voluntaristic')
A Reaction
I'm going off the idea that being a member of large society is voluntary. It can't possibly be so for most people, and it shouldn't be. I'm British, and society expects me to remain so (though they might release me, if convenient).
Book Reference
Wolff,Jonathan: 'An Introduction to Political Philosophy (Rev)' [OUP 2006], p.40