Two key points, which we probably agree on: (A) There are various flavors of social contracts. (B) Acceptance of any one social contract is a statistical thing, not a binary thing.
The most basic idea of a social contract is the legitimacy of a government to exist and function. This might mean to carry out various agreed-upon roles. And/or it might mean to operate according to some defined procedures, like the rule of law. The vast majority of people either consciously accept this or live as though they do. Of course there is variation on the proper role of government: does it include national defense, maintaining order, creating fair markets, collecting taxes, protecting civil liberties, internalizing economic externalities, investing in R&D, providing a healthcare floor, fighting corruption, etc?
The most basic idea of a social contract is the legitimacy of a government to exist and function. This might mean to carry out various agreed-upon roles. And/or it might mean to operate according to some defined procedures, like the rule of law. The vast majority of people either consciously accept this or live as though they do. Of course there is variation on the proper role of government: does it include national defense, maintaining order, creating fair markets, collecting taxes, protecting civil liberties, internalizing economic externalities, investing in R&D, providing a healthcare floor, fighting corruption, etc?