Strictly speaking the sperm and the egg are alive. Therefore life does not begin. Instead its a continuous cycle of birth and rebirth. There are those for whom this answer is not enough. They believe in the individuality of the soul, and want to know when it enters the body and begins a life. Its not a political question. It is a matter of religious belief and because of the separation of church and state, does not belong in our America political dialog.
But that does raise the question of the individuality of the soul. Like Tom Joad said, "Well Mama, looks like one big soul to me."