The writer forgot to add the "Roe" effect. More children have been born into conservative homes than liberal homes in the past 30 years. The 1.3 million abortions every year have not been evenly divided into pregnancies of conservatives and liberals.
Liberals have reduced their own pool of new voters voluntarily.
May I ask you a question? Could it be that the liberals who are having abortions, are having them at a very young age, but might have children when they are older?