I have a liberal aquaintance who is unabashedly and proudly PRO-ABORTION. He told me recently that he's in favor of as many abortions as possible. The more the merrier. He was "dead" serious and said it quite matter of factly. This is a guy who is a very prominent local "progressive" and very active politically. It literally made me sick to my stomach.
These attitudes, according to this book, began in America but spread around the world, contributing to Germany's involvement with horrendous medical experiments and eventually the holocaust.
I think we need bumper-stickers which state: "Pro-Choice Republican: I don't care how many of their own babies the Democrats kill."
The first thing you have to do is stop referring to him/her as "liberal" because he's not. He's a leftist.
I've found that making this distinction really ticks them off.