Can you abort a baby right before its born? No, thats called murder. So why doesn't that apply to the earlier stages?

This is a reasonable question and you shouldn't have been downvoted for it.

But to answer that question we should follow it to its logical implication:

(1) Enforcement would be impractical or totalitarian. Supposing the government ruled abortion illegal and made it a crime equivalent, in seriousness, to murder, there would need to be checks and enforcements of all pregnancies. All missing persons or homicides must be investigated. So too would all failed pregnancies, if the crime were seen as on par.

Imagine the burden this would be to enforce, the resulting extraordinary violations of privacy (even in women who intend to keep their children, as they would need to be minded over too), and the power that would have to be ceded to the local government for the sake of that enforcement.

"Are you still pregnant? We checked your medical records." "Ma'am, we have to make sure that you still have your baby." "Can you prove that your miscarriage was natural? You may have to prove that in a court of law. If you cannot afford legal representation the state can provide you with an attorney."

And even if it was proven that a woman had an abortion, what should the consequences be? Imprisonment, a fine or, in the case of twins or multiple abortions, execution? If prison, what if she already has kids (many do) -- to whom should their custody be entrusted?

(2) When does a cluster of cells become a 'person'? I'm not here to debate religion. But it is clear in the medical field and to common sense that a life does not come into existence at conception. For the first couple of months there is no baby to speak of but a tightly knit cluster of cells. A cluster of cells has no rights and we as human-beings owe it no moral obligation. Eventually this could become a life, but where this point begins is the moral question, and generally this is the basis on which the final deadlines for abortion are set -- at 12 weeks it becomes a life in some states, here in Australia (specifically Queensland), we consider it 24 weeks. Whatever you feel is the case, you must set your own point at which you feel there is a difference between the termination of a cluster of cells or that of a person. But you must set that point. And after that it's not a debate about whether there should be allowed abortion, but what timeframe constitutes one.