The first point I would like to raise is that there is inherently a difference between the legality of an issue, and whether it is ethical or not. My main argument is that abortions should remain legal, here is why.
As I stated before as a comment to someone when discussing abortion it is important to define what makes a human, a human. Is it our self-awareness, our consciousness? This question is important because if you can determine what makes a human being a human being you can decide for yourself whether abortion can be considered murder or not. Bottom line is murder is not ok, but if something is not a human being yet, can it really be considered murder? I would say not.
If you agree that removing something that is not a human being yet is not murder then you have to ask yourself when exactly does a fetus become a human being? There are many answers to this question, but the real answer is nobody knows, it is something you have to decide for yourself. To me, I'm a human because I am self aware, and I have the ability to live on my own, that is, I can breath on my own and my body functions on it's own without my mother's help. Certainly a baby cannot take care of it's self, but it does know when it is hungry, thirsty, and hurt. There is a specific time when a fetus begins breathing and thinking on its own. For the life of me, I cannot remember the name of the process, but its right around 26 weeks. To me it is at that point an abortion is wrong. Before that, a fetus is nothing more than a clump of cells attached to the uterine wall. For that reason, first tri-mester abortions should remain legal.
Furthermore, a woman has to think of her rights. Why should the government, or anyone for that matter, be allowed to tell a woman what she can or cannot do with her body. We live in a free society. One where we are allowed to make choices for ourselves. We decide what we put into our bodies, and what we take out. The issue of abortion should central around this. At what point does it stop being our bodies that we can do as we wish with, and start being the governments?