Are We Trying to Bring It All Together?

In a Gallup survey, 60% believe elective abortion should be legal in the first trimester. If we want to hold on to human equality, we would have to root it in what's equal in all of us, which is not our cognitive abilities or development, but something more like our human nature. I don't see a logical reason as to why if human beings develop gradually their moral worth ontologically that birth is when they're assigned that full moral worth.