Kids respect mothers who are in control (or at least act like we are!)
The big world is a scary place even for kids who think they know all the answers. Most of the resistance to authority, the actions that a parent deems difficult, are fear-based reactions that the child has designed to create his own security. The child is playacting that he has control because he is convincing himself that this is the only way he can cope.
In contrast, a kid who sees Mom regularly stepping up to handle situations, also relaxes and lets down his guard and the defensive arguing/resistance is not necessary. Children want to know that MOM is in charge, that she will take care of things and when MOm consistently handles problems the trust increases as does the respect and the compliance.