People keep telling me that abortions are ok, but how can you justify killing a child?
Your question reflects your own misunderstanding of our form of government.
Our nation is a constitutional republic, not a pure democracy. In other words, you may not use (or abuse) the power of the state to impose your morals on everyone else in society.
If you experience an unwanted pregnancy, then you ... as an individual ... have the right to determine for yourself whether you will end or continue that pregnancy. In making that decision, you may consider your own sense of morality. If you believe terminating the pregnancy is immoral, then that belief will be an important consideration when you determine your own course of conduct. You don't have the right, however, to impose your sense of morality on your fellow citizens.
Years ago in a "60 Minutes" interview, Justice Scalia said the following:
"What is the connection between your Catholicism, your Jesuit education, and your judicial philosophy?" Stahl asks.
"It has nothing to do with how I decide cases," Scalia replies. "My job is to interpret the Constitution accurately. And indeed, there are anti-abortion people who think that the constitution requires a state to prohibit abortion. They say that the Equal Protection Clause requires that you treat a helpless human being that's still in the womb the way you treat other human beings. I think that's wrong. I think when the Constitution says that persons are entitled to equal protection of the laws, I think it clearly means walking-around persons,"
Thus, the decision whether to terminate a pregnancy or carry it to term belongs to the pregnant individual. Only when the fetus is viable, i.e., capable of surviving outside the womb, then the State has a legitimate interest in preserving that life.
If the law was otherwise ... if the state had the power over procreation ... then the state would have the power to prohibit abortions or require abortions depending on the legitimate interests of the state. It would be a power pendulum that swings both ways. Thus, like China, a state could have a legitimate concern for over-population and institute a one-child only law.
But, the state does not have that power.