What mechanism? Publication (in all media forms) of debate and guidance, and the ability of individuals to require explanation if guidance deviates from established norms/acceptable practice. Why that mechanism? Because public scrutiny of the minutiae of rule and governance is anathema to the ruling classes and their puppets. It constrains the guide as well as the decision-makers/legislators to directing their attention to the public interest, not their own. If you knew that maybe 100,000 individuals or more would scrutinise every bit of guidance, and/or every legislative decision, how prepared would you be to sell your liberty and/or your reputation?