Killing a person would be legally murder. Abortion isn't murder, therefore it isn't killing a person.
Legally, it's not murder if it's done in the first trimester of a pregnancy. However, you are stopping the development of what would eventually become a human being. Some people believe that doing that is in fact murder.
That is the moral conundrum around the abortion issue in my opinion.
I don't drink, so if alcohol was illegal I wouldn't care in the slightest. However, those that know a little about history (This is the "prohibition" part in your textbooks, kids), will know that it was tried before, and was a huge failure. Banning something which people before have had rights to is difficult. But I'd rather alcohol become illegal than those drugs become legal.
Firstly, I'm going to postulate that if alcohol was discovered today, it would be contraband. It's just as dangerous as most hard drugs, but the health effects aren't felt until later in life.
Secondly, why did prohibition fail there kiddo?
Finally, why couldn't other drugs (marijuana in particular) be legalized, regulated, taxed, and require you to have a permit to sell like alcohol and tobacco? All three have the same basic health effects and all three have significant effects on the brain and body during/after consumption.
Mainly because most stoners don't have enough money to make a difference by lobbying to the government like alcohol and tobacco do.