Formal authority and popular acceptance

Your Honor ,
I have a question about formal authority .
I didn't understand why the acceptance of a norm by the entire nation gives formal authority to that norm .
(I thought that if group Accepting norm, then Allow that you received The norm Come in. To define The group. French received drink at leastglass one of wine In the long run noon. then all who that is not does you this Ino French. By definition. but this will cause Who is Jewish? that is not AcceptingThe Talmud As required Ino Jewish By definition. And that visible me not right.)
I apologize in advance if you 've already explained this ( but I could n't find it ).