Abortion is not murder, it is self defense. I say this because I do not recognize the right of any person to use or occupy another person’s body without that person’s consent. It is also for this reason that we would not force someone to give up a kidney, or any other organ, to save a close family member (though they are free to do so voluntarily). That said, if another being is occupying your body or compromising your bodily autonomy in any way you can and should have the right to defend yourself, and expel this being with force if necessary.
That is my position. Of course, the all too frequent reply is “shouldn’t sluts just shut their legs” or something to that effect. While I would never put it so vulgarly, I do acknowledge the underlying point that if more people made more responsible and better informed sexual decisions there would be less need for abortion and that promoting more responsibility would certainly be a worthwhile goal (however, I do not think demonizing sex or promoting abstinence only education is conducive to this). That said, I reject the underlying implication that if someone consents to sex they should be required to carry to term whatever new life emerges as a result of their decision (it should also be noted that this argument cannot be applied to non-consensual sexual encounters).
The problem with whole “you consented to sex, now you have to live the consequences” argument is that we do not deny someone the right to defend themselves simply because they contributed to the situation at hand. For example, if I invite someone into my home, and they physically attack me or attempt to steal my possessions, few would argue that I have no right to defend myself against these aggressions because I contributed to the situation. Nor do we deny people the right to seek medical care, even if they contributed to their condition. Smokers are free to pursue treatment for their lung cancer, last time I checked, just as sunbathers are free to pursue treatment for their skin cancer.
So there you have my argument for viewing abortion as self-defense issue. It may be noted that this argument, says that a woman may forcibly remove a fetus from her body, but it does not say, you have a right to terminate it’s life afterwards, if it is capable of surviving outside the body. It also should be noted that the argument presented here assumes the personhood of the fetus from the get-go, and therefore does not rely on controversial assumptions about when personhood begins.