Far more than abortion is at stake: There are measures that establish legal principles that will be and, indeed, already have been used to justify arrests of and forced medical interventions on pregnant women.
Most people identify Roe v. Wade with a single landmark judgment. Lost in these debates is Roe's altogether distinct holding that the state's interest in "potential life" constitutes a valid reason to regulate reproductive conduct.
"Personhood" for zygotes cruelly subverts the very idea of a culture of life and potentially criminalizes every pregnant woman. Are you really cool with that? Even if you personally would not chose an abortion?