"Well, you don't want a theocracy, do you?"
"This country is not a theocracy."
"You want to impose a theocracy??!?!"
This sentiment is the moral equivalent of "you don't have the right to impose your morality on others," an argument whose silliness I have written about elsewhere:
This "bayonetting our own" line is just a variant of the old pro-abortion argument, "No one has a right to impose their morality on others." Well, what if my morality says I DO have that right? By telling me what to do, aren't you assuming that YOU have the right to force this arbitrary standard on me? If you REALLY felt that way, you would have to remain silent, recognizing that I may not share your sentiments.Generally speaking, the person who trots out the "You don't want a theocracy, do you?" line is an atheist who wants to imply that you are a sleazy, violent, anti-democratic nutcase. But even if the individual who trots out this line is a mis-guided theist, the argument is easily torn apart.
So, if the argument is so stupid from a logical standpoint, why would anyone say it? Well, it serves three purposes:
It's pure ad hominem attack, and it's sleazy.
Question: America is a secular society, right?
Answer: Well, it is supposed to be. And it would be if you nasty little religious people didn't keep shoving your morality down our throats.
Question: Should laws create the greatest good for the greatest number?
Answer: Of course! That's precisely what theocracy does not do! It only benefits the minority at the expense of the majority!
Question: Do you like all the laws that American society imposes on you? Are you happy with all of them?
Answer: Well, no one is happy with all the laws. That's the price of living in a pluralistic society!
Question: Indeed it is! Since living under laws you don't like is the price of a pluralistic society - a price you are happy to pay - what difference does it make if you happen to live under a different set of laws you also don't like? From your point of view, it shouldn't make any difference at all. You aren't living under laws you like now, if we changed the law to a theocracy, you would still be living under laws you don't like. So, it's no loss to you. We're still pluralistic. As you point out, no one is happy with all the laws. So, we can have a lot of different groups who don't like the new theocratic laws, and it doesn't change the current situation at all.
Meanwhile, there is a significant subset of Americans who would LOVE to live under a Catholic theocracy. So, in order to implement your rules and do the greatest good for the greatest number, we really should impose a theocracy, as it makes no net negative difference to those who don't like the current law set, and it would make a great positive difference for those who would like to live under a Catholic theocracy.At this point, they will start huffing about how it makes an enormous difference, but they won't be able to tell you what that difference actually is.
I am now authorized to reveal what the essential difference is. The difference between living under secular law vs. a theocracy is simple: by having everyone live under secular laws they don't like, everyone is forced to tacitly accept the idea that secular laws are superior to all other kinds of law. If we force everyone to live under Catholic (or Islamic or Jewish) laws they don't like, everyone would have to tacitly accept the idea that Catholic (or Islamic or Jewish) law was superior to secular law.
It isn't the "living under laws I don't like/believe in" part that upsets them.
It is being tacitly forced to accept the idea that Catholic law really is the best form of law.