...The Gospel is the Gospel, and to mention it is implicitly to bring in whatever is necessarily connected to it—including the Church. With that in mind, the principled objections to a Catholic society don’t stand up to much thought. All men are unjust, except maybe a few saints, most actual Catholics put their main efforts into worldly goals, and harsh things could be said about the Church as a human institution. It is nonetheless right for believers to think of themselves and their communities and institutions as Catholic, even though there may be some less-than-saintly things about them.
Life must go on even though men are imperfect. Individuals and societies need some sort of guiding principle, and the guiding principle they accept helps define who they are. That remains true even when they abuse and fall short of their principles, as they quite generally do. A bad Catholic is a Catholic, he’s just a bad one, and if he calls himself Catholic and his commitment makes some difference to how he acts he’s doing as well as most of us. The same would be true of an imperfectly Catholic social order, which any social order calling itself Catholic would no doubt be.
...A Catholic society could, for example, be liberal and democratic in many ways. Liberal goals and institutions are often good, but only up to a point and not as the highest standard. So the judiciary could be independent, accused persons could be tried by jury, high officials could be chosen by popular vote, and there could be extensive freedom of discussion and belief. The point is that pure choice would be limited by the public good, as it always is in one way or another, but the public good would be determined in a Catholic rather than techno-hedonistic sense. So actions and utterances at odds with Catholicism would likely be treated much as practices and utterances at odds with advanced liberalism are treated today. To pick an example, instead of worrying about hate speech the authorities might worry about gross impiety, and look for a sensible way to respond to it while respecting other concerns.To the average SWPL, "Catholic society" conjures up images of the Grand Inquisitor burning their manic pixie atheist girlfriends and their gay hairdressers at the stake while their congressmen solemnly read aloud from papal encyclicals on the floor of the capitol. Ah, if only, if only. In reality, a Catholic society would share some superficial similarities with a liberal polity. The big difference would be the principles upon which public discourse hinged.
In our liberal theocracy, discrimination is the most terrible-horrible-no-good-very-bad thing in the universe, and tolerance is the source and summit of all that is good, true, and beautiful. Like Malcom McDowell in Clockwork Orange, we have to be strapped into chairs and our eye lids pulled open to watch propaganda films until we can dutifully recite the correct platitudes about how multiculturalism makes us so much better than our stupid racist grandparents.
If the purpose of government is to ensure equal freedom for all, then existentially there must always be an oppressor to overcome. You might have been under the mistaken impression that same-sex "marriage" is the greatest battle of good and evil of our time, but that only shows you're stuck in the past. No, the real struggle for the greatest good is now focused on the transgendered. Get with the times, bigot. You don't want to be on the wrong side of history do you?
In a Catholic society, the recloseting of gross impiety and immorality would seem as natural and necessary for the public good as the closeting of racism is today. Catholicism is not simply a series of laws that we must obey, although it does include that aspect of life. Catholicism, as Kalb says, is a way of looking at the world. My atheist friends are often confused by this notion when I put it that way. Catholicism is not something you just do on Sundays and spend the rest of the week living like a technocratic hedonist like everyone else. To be sure, many Catholics do just that. But bad Catholics are still Catholic. Catholicism just is how the world works. I believe in the existence of God the same way I believe the sun will come up tomorrow.
When we speak of Catholic novels, TV shows, movies, music, and art, we don't necessarily mean those things must explicitly speak of the Roman Catholic religion or take place in an ecclesial setting. The Lord of the Rings is a deeply Catholic work of literature. Making a Catholic culture will happen one soul at a time. I won't live long enough to see a Catholic society but I can do my part with the time I have.
Supernature abhors a vacuum. Christianity is retreating from the public square more every year. When it's gone, something will come to replace it. In Europe, that something will most likely be Islam. Here in the US it's looking like Moralistic Therapeutic Deism. Some might argue for secular liberalism to be ultimately triumphant, but it's too irrational and inhuman to survive for more than a few generations. Catholicism is the only rational alternative. Get to work men.