Below follows one paragraph from the third chapter of Political Visions and Illusions. This illustrates two of the ways in which conservatism can indeed be considered an ideology. There's more to my argument than this, but I'll whet the appetite with these remarks only:
What conservatism as a whole seems unable to do is to formulate a generally accepted, transhistorical criterion by which to distinguish what in a tradition is worth saving and what ought to be discarded. To be sure, many conservatives profess to believe in the existence of what [Russell] Kirk calls “an enduring moral order” in which “human nature is a constant, and moral truths are permanent,” and by which our multiplicity of traditions might be judged. In this respect such conservatives are closer to a Christian understanding of the world than to an ideological belief in the unlimited malleability of the world to suit our own human ends. Yet even on this issue conservatives err, first, by failing sufficiently to distinguish the traditions, institutions and mores of their own society from the transcendent order they claim to uphold, and, second, by underestimating the dynamic character of that order. Change and development are not defects; they are an integral part of creation as God has structured it. Conservatives have difficulty recognizing that structure and change, far from being opposed, in fact presuppose each other (p. 87).