Since it is the Commons that controls debt and taxation, this source of authority would have both affirmed their new place in the political system and given them precisely the powers they desired to possess so that they could enact the policies they sought. But at a deeper level the revolution was already beginning, because the question at hand was one of the source of authority - a change in the means of doing business. Once the discussion is opened it is not easily closed. The Commons idea was laughed down, and the revolutionary nature was opened fully. After the Third Estate was told, in effect, that it had no power, the next step was inevitable - an attempt to sieze power by whatever means.
Power become the policy.
After long debate, several unwieldy and compromise-laden ideas for what to call the body were put forward and rejected. It was then pointed out that you cannot compromise with another side that does not recognize that they need to give any ground to you at all. Thus the authority of the body could not rest on logicalist doctrines of an Estate as part of the sovereign, such as Voltaire pursued, but had to flow from the more radical doctrine of Rouseau - that there was an innate will that recognized what was correct, and that truth consisted of the recognition of this will. This in one compact expression declared what the nature of power was and the means by which the group intended to amplify decisions - by proclaiming them as popular will against a minority that did not represent that will. Each successive wave of governance attempted to proclaim itself as the embodiment of that will.