This is a frequent error with a lot of people in the Church, not just laypeople or "liberal" Catholics, but quite Orthodox people, as well. In many cases, I really don't think they quite understand the full dimensions of the Church's authentic teaching on the subject. If they did, they would realize that the Church's teaching on the subject lines up fairly well with what we call basic conservatism.
So what to do about it?
Well, we need to be well versed in the fundamental principles of the Social Doctrine of the Church. These folks can argue with you, believing that you are just a hard-hearted Republican...until such time as you can actually teach them using the correct verbiage from the Church and referencing the correct fundamental documents from the Church. If you can do that and express it, not in terms of judgement, but in terms of doing authentic help for people, you might be able to get through. Since I have learned what I have, I've had about a 40% success rate (I define that as being able to get a person to consider authentic respect for human dignity and the importance of the principle of subsidiarity). But that's some...so I consider it to be worthwhile.
Anyway, if you're interested, you should consider buying the Compendium Of The Social Doctrine Of The Church for your reference shelf. It is a tremendous read and will provide you the ammo...authoritative Church teaching...to illustrate that conservatism is the authentic Christian and authentically compassionate way to live and relate to others.
Catholic ping for your consideration...
More evil from John Rawls.
Replacing charity with the use of force is anathema.