This disputes the author’s assumption that the society-as-family metaphor is less popular than the society-as-body metaphor. If both metaphors are equally widespread, then the society-as-body metaphor cannot be popular simply because it justifies authoritarian rule.

This strengthens the critic’s argument. It explains why the society-as-body metaphor would be politically useful to authoritarian governments.

This doesn’t say the society-as-body metaphor is popular in nonauthoritarian societies. It may be quite rare, in which case its relative popularity in authoritarian societies still supports the argument.

This doesn’t say the society-as-body metaphor becomes less useful to authoritarian leaders over time—they can search for new metaphors without abandoning old ones.

This strengthens the argument. It supports the critic’s claim that metaphors are popular to the extent they’re politically useful, since it suggests the society-as-body metaphor is much more popular in authoritarian societies than in liberal democracies.