Have you ever seen this bumper sticker?Here's the problem. A pro-life advocate makes a moral claim that he/she believes is objectively true: that elective abortion unjustly takes the life of a defenseless human being. The advocate of abortion-choice responds by turning that objective truth claim into a preference, like preferring chocolate ice cream to vanilla.
But this misses the point entirely. Being pro-life isn't about what I like better, it's about what is true. I don't oppose abortion because I find it distasteful; I oppose it because it violates rational moral principles.
So this bumper sticker, no matter how passionately it is slapped onto someone's car, is really irrelevant to the abortion debate. It treats the unborn like an ice cream flavor instead of a human being.
Imagine a bumper sticker that read, "Don't like slavery? Then don't own one!" Are we ok with that as a society? Then we shouldn't be ok with one for abortion either.