Why should the US restrict abortion access to that extent, given the historical consequences of restricting abortion access?
"Blacks commit a disproportionate amount of crime, especially young black men. Therefore black mother's should be allowed to smother their 5 year olds in order to prevent them from growing up into criminals."
The above argument is wrong because the 5 year olds are persons. Regardless of their future potential to cause harm, they have a right to life because they are persons. Unless you're a utilitarian or something similar, the question of abortion ultimately boils down to one question "When does one become a person?".
I agree that the pro-life movement needs to have a broader agenda, but the social consequences argument doesn't really address the pro-life movement's issues and it has the potential to lead to monstrous results.