From Mirror of Justice, a blog dedicated to the development of Catholic legal theory...
Now, Eduardo and I (and Murray and St. Thomas!) agree that not all immoral conduct need be, or should be, illegal. It is immoral, I assume, to relish in one's mind delicious revenge against one's enemies, but only a monstrous legal regime would make such relishing illegal. It is wrong to engage in cruel and hateful speech, but we do not -- and should not -- outlaw such speech. It is wrong to cheat on one's spouse, but no one should go to jail for it. And so on.
Eduardo and I agree that abortion is immoral. So, should it be illegal? Or, to refine the question slightly, "how important is it that abortion be illegal, if its incidence can be reduced substantially by means other than regulation"?
For starters, I have to say that Roe and Casey should be opposed, and overruled -- that is, it should be, again, permissible to regulate abortion -- for reasons independent of abortion's immorality. They are bad constitutional law, and the fact that these mistakes are more likely to be fixed (though, obviously, not certain to be fixed) by judges appointed by Republicans is a strong reason to prefer Republicans. That said . . .