The argument here can't be boiled down to "This is or is not a person." The real argument is whether it is in your personal values to consider a fetus at whichever point to be close enough to be considered worth saving. The arguments over whether it is a woman's right to choose, whether the process is humane, etc. are all secondary to that main point. And the answer here is that every person's response is somewhat unique. The difficulty arises when this spectrum of personal values is polarized to a single yes or no question: should abortions be allowed to happen? Almost everyone's (real) answer, is "Yes, but...". Some are "Yes, but only in extreme cases." or "Yes, but only very early." or "Yes, but only with after a serious discussion with a therapist and a doctor." Even those who support abortion at points considered to be very late in the usual arguments (third trimester, for example) would probably say that aborting two weeks before the expected due date would be wrong, or at least a poor choice. So rather than saying that anyone who is against abortion is a "republican who [doesn't] understand or believe in science," understand that there is really no right answer to this question. Human gestation is not a simple process, but it is definitely connected to our personal beliefs and values about life and humanity. Disregarding that connection will only alienate you.