The biggest complaint I have about social liberalism is not the libertarian attitude about social issues. It's that it's often adopted inconsistently. A true libertarian doesn't necessarily have this problem, and social liberals who don't believe in genuine morality aren't subject to this particular criticism. The problem here is when someone takes liberal views on sex, abortion, drugs, tobacco, etc. by saying that you can't legislate morality while also saying that we need to have strong laws against murder, rape, other violent crime, etc. The reason for taking the second attitude generally has to do with protecting people from these criminals. That sort of action is wrong, and we need to stop it. The problem is that this is legislating morality. Dennis Miller illustrates this inconsistency very well in a New York Times story today:
"If two gay guys want to get married, it's none of my business. I could care less. More power to them. I'm happy when people fall in love. But if some idiot foreign terrorist wants to blow up their wedding to make a political statement, I would rather kill him before he can do it, or have my country kill him before he can do it, instead of having him do it and punishing him after the fact. If that makes me a right-wing fanatic, I will bask in that assignation."
Then he follows it up with: "I think abortion's wrong, but it's none of my business to tell somebody what's wrong. So I'm pro-choice. I want to keep my nose out of other people's personal business. I guess I fall into conservative when it comes to protecting the United States in a world where a lot of people hate the United States."
If abortion is wrong, why is it wrong? If we should protect the United States from those who hate us, shouldn't we also protect what are at least undeniably human organisms who have no voice and who are continually killed by those who don't care much about them, something currently tolerated by a country that turns a blind eye and changes the subject by talking about some absolute right to do whatever you want with your body regardless of whether it affects anyone else as long it doesn't affect anyone else who's been born, as if the Constitution gives any such right. Surely the argument Miller uses about protection with the foreign policy issues should also apply here, if indeed he's right that abortion is wrong. Why say one is urgent and needs immediate attention, including the death of the killer, whereas the other just is something that's wrong but shouldn't be prevented. If Miller wants to be consistent, he needs to wonder whether those who perform and commission abortions should be stopped (not that it would require killing them in this case) before they do something wrong also.
There may be more sophisticated ways to avoid this problem with some socially liberal views (e.g. on sex, though look through some of my earlier discussions for some hesitations in this concession), but the pro-choice view doesn't seem to me to subject to that once you admit that abortion is wrong.