I could, for a short time, perhaps manage to keep them alive. Why would I be charged with murder unless I tampered with the electricity and caused it to go out? Are they human if they can't breathe on their own? When do they stop being human?
For the same reason you want to call a person who has an abortion a murderer. If a woman doesn't want to "breathe" for her unborn child or doesn't want to "eat" for her unborn child, etc. then it isn't murder -- using the standard you are using for the person who can't breathe on their own who you have to assist.
Yes, for most of human history, a person who could not breathe on their own would die. We've changed in the last century or so, developing machines that breathe for them. Never have we forced other people to do their breathing for them long term -- nor do you appear to be in favor of such laws. It isn't murder, if you are involved in an accident that causes a person to stop breathing but can be saved with medical treatment, to keep breathing for them until help arrives -- even if the accident is your fault.
Your issue is that your examples aren't equal. If we could put fetuses in a machine and bring them to term, like we do with the person on a respirator, then the point would be equal. I'd even concede the point if a fetus could be removed and then connected to a new "mother."
The other flaw is you claim a baby isn't independent but that isn't true -- it is independent of the mother. Yes, the baby still needs to be fed and otherwise cared for, it will die if no one cares for it. Yet that doesn't have to be the mother -- most people can do it and, and frequently do (fathers or in the case of abortion).
It was the basis of my point, that went over your head -- is it murder if a person can't breath (such as electrical failure) and you don't keep them alive? That is what you are telling the person who has an abortion -- if they stop breathing for the fetus (by disconnecting the fetus from their body) then you believe it is murder.
And don't get me wrong, I'm not making any claims about abortion -- there are various good moral arguments that can be made from both sides. We should work to lower the number of abortions (legal or illegal). My issue is that your argument was flawed and is hurting you in this thread more than helping.