In the Errors of Ideology chapter in the Politics of Prudence, Kirk discussed “ideology” as the tendency to think that we can find a “simple saving truth” or formula that will then substitute for true principles and character.
In reading the link that someone thoughtfully supplied on the prior page to the original article which had some direct quotes of the Pope's homily and its context to the teachings found in the biblical quotes he cites, this appears somewhat the sense of what he was saying.
I know people of faith that in expressing or discussing their faith, seem to elevate a particular item to a “door shutting” condition (the Pope's analogy) and say that others are not “Christian”, “saved”, or any of a number of things if they don't believe in “apostolic succession”, “sola scriptura”, “sanctity of life”, or some other sole formulaic statement above, or instead of, all else.
Kenneth Minouge, Russell Kirk and many other philosophic writers have pointed out the limitations of the term and not wanted to see it substituted for broader terms of belief or principles.
I understand what all these wise men are saying.
But they are assigning their own meaning to the word, and then denouncing it as being “bad.”
A word means what it means, not what you, I or Russell Kirk thinks it ought to mean.
American conservatism is an ideology, as is every other belief system. Which means there are good ideologies and bad one, and true ones and false ones.
The point is not to “reject ideologies,” as this is not possible. It is to choose an ideology that is true and good, preferably of course True and Good.