The child in the womb is an unique individual. In the general course of nature that child will live a long life. Yes, it is dependent on the mother. It's also dependent on others for its survival outside the womb.
A majority of Americans are personally opposed to abortion, and IIRC, a majority are in favor of the status quo WRT abortion's legality. Naturally, Americans have an aversion to the interjection of the state into family life, though that's a fading instinct which will be gone in a generation.
Abortion, as it is practiced, results in the termination of non-white individuals at rates far in excess of those of whites. A reality in which white "progressives" clamor for the support of an organization which purposely locates itself in majority, poor non-white neighborhoods to exterminate large numbers of non-white children would seem like a Klansman's fantasy come true. Jesse Jackson once thought so until his patrons didn't want to hear that anymore.
In American culture, new life is ultimately seen as an additional material cost, a limitation on an individual's freedom, rather than a blessing, and this cuts across many socioeconomic groups. As it relates to public policy, abortion is a de facto method to manage the poor population.