Anti-repeal is simply using children with DS as the sunny face of their campaign. It never occurs to them that given the extended lifespan of girls with DS, they will also be subject to the same laws regarding the provision of abortion, because they are not supposed to ever become sexual beings.I don't think they believe women with DS can get pregnant, like they're a Barbie Doll "down there". Antichoice barely treat kids with DS as actual people, preferring to use the puppy substitutes as props in ad campaigns and dropping them when they're less cute, but really being clueless about the complex needs of people with DS. They'd have a sh!tfit if they thought adults with DS wanted agency to have sexual relationships.
Nor do the campaigners want to know that girls and women with DS have an increased risk of sexual abuse which may result in pregnancy. That does not fit with the narrative.