Conservative Christians in America can exhibit a strange obsession with fetuses. They appear to be willing to sacrifice any level of women's personal autonomy and civil rights in the "interests" of the fetus, even though similar measures would not be taken to protect the interests of a fully-grown and conscious adult human in analogous circumstances. Perhaps this is because their agenda is less about the alleged interests of the fetus and more about promoting a patriarchal culture where women are kept subordinate.
It would be unusual, if not impossible, for people to adopt political positions in isolation, which is to say without those positions being interdependent with a variety of other political positions. Even if this might be true with a few individuals, it's not true of entire political movements. Attempts to explain or understand the anti-choice movement in America requires us to therefore take into consideration positions on contraception, feminism, marriage equality, rape, women in the workforce, religious dogmas on the roles of women, welfare spending, education policies, and so forth.
In Sacred Choices: The Right to Contraception and Abortion in Ten World Religions, Daniel C. Maguire writes:
There is ample reason to say that this newborn love of fetuses is but a cover for the patriarchal fear of the free woman who is appearing in our day. Can we really believe that patriarchal Catholics, patriarchal Protestants, and patriarchal Muslims, after centuries of warring with one another, are suddenly and stunningly bonded by fetus-love? [...]
What lurks beneath family value rhetoric on the right -- among Protestants and Catholics -- is a kind of sweet love ethic that loses sight of social justice and the needs of the common good. This makes the right the darling of the harsher modes of capitalism. The suppression of social conscience and concern for the poor that is masked by family value piety, really intends, in [Beverly] Harrison's [former professor of Christian Ethics at Union Theological Seminary in New York] view, "to make Christianity the 'handmaiden' of 'the Market God' who brooks no rivals."
So-called "family values" are really the faith-based "values" of rigidly defined gender roles — not just in the family, but also in the workplace, politics, culture, and society generally. These are the "values" of white, Christian men retaining public positions of privilege, power, and dominance while women are relegated to more private and hidden positions where whatever "power" or "skills" they are allowed to exercise are automatically devalued. No matter how much some may protest that the role of housewife and mother are critical for the future of society, for example, men who choose to adopt such roles are derided and their masculinity is questioned.
Glorifying the fetus is an effective tactic in promoting a patriarchal agenda because it allows people to subordinate women's autonomy and civil rights without admitting that that's what they are doing. They can claim altruistic motives on behalf of the fetus in a manner that is analogous to how more general civil rights are narrowed on the basis of calls to "protect the children" from some amorphous threat. So long as somewhere, somehow, some child may be threatened, it's acceptable for the basic liberties and civil rights of everyone to be constrained.
In both cases, it is clear that concern for the children or the fetuses isn't really motivating them because all their "concern" seems to end once we stop talking about limiting the rights of others as part of the protection efforts. If you try to turn the conversation towards increased food assistance, better education, environmental cleanups, and so forth, suddenly you're a socialist who is trying to inappropriately infringe on the economic liberties of the wealthy.
This is also why contraception is becoming a focus of concern by the same people: contraception allows women to avoid becoming pregnant and thereby becoming subject to fetus-based restrictions on female autonomy. A woman who chooses when and if she becomes pregnant is a woman exercising personal autonomy and personal choices, precisely what theses religious conservatives oppose. No fetus even exists yet, so obviously the opposition to contraception isn't motivated by a desire to defend one. Instead, it's motivated by a desire to create more fetuses and thus create more situations where women can be denied the ability to exercise personal autonomy.
It's not just female autonomy that is targeted by religious conservatives,. All autonomy is subject to attack because personal, human autonomy means having the ability to act contrary to the will of God. Autonomy is simply another label for blasphemy and apostasy as far as some Christian Nationalists are concerned. It's not a coincidence that the most frequent targets of censorship or other restrictions on civil liberties are also often the ones which create the most consternation for devout religious believers.
It's theoretically possible to favor criminalizing abortions while opposing the establishment of a stronger faith-based patriarchy throughout politics and culture, but working for the former in today's political context means helping people who are working for the latter. It's a bit like someone favoring a national fingerprint and DNA database of all citizens while opposing the establishment of a fascist or dictatorial government. Sure, it's theoretically possible, but even in the current climate supporting the former means making the latter much more likely; in a climate where there is a large, powerful political movement trying to achieve the latter, no one pushing the former could legitimately feign ignorance or innocence.
So regardless of how strongly they protest their opposition to patriarchy and faith-based oppression of women, anyone who supports restrictions on or the criminalization of abortion is objectively aiding and abetting precisely those goals. Politically speaking, what's the difference between them and someone who does indeed actively desire those goals?