Professor Perry and Consensualism

According to Micheal Perry, the constitutional right to abortion provided for by Roe v. Wade should be limited to cases of rape, incest and child’s deformity because the public consensus does not extend to other circumstances.
Perry presupposes that there should be a wide consensus on the meaning of a provision.
However, this assumption is not tested under the condition of social consensus because it would be difficult to achieve a large agreement on this point.
For example, if the meaning of “liberty” relied only on how people used the word, liberty would not exist, and there should be only liberty talk.
Then he justifies his assumption on the basis of democracy: the only way to legitimize the power on unelected judges who invoke a principle is doing it on the ground of social consensus, in order to maintain democracy.
But this conception of democracy cannot rely on a social consensus: in this view, individual rights against the community would not exist, because the community would be the very source of law through its consensus.
Therefore, Perry’s conception of democracy is based on what he intends as the best understanding of democracy. In this sense, in absence of consensus, it is a moral reality which justifies his search for social consensus. Both Perry and Black de facto rely on controversial conceptions of democracy that they leave undefined and both thus support a fusion of constitutional law and moral philosophy.