“If you don’t agree with abortion, don’t have one.” This retort would be fine, though superfluous, if made after the discrediting of the key premise of the essay: that abortion is an unjust attack on a human being in violation of her most fundamental right. It is a non sequitur as a substitute for that discrediting, in the same way as it would be to say, “If you don’t like genocide, don’t commit it” or, “If you don’t like school shootings, don’t shoot up schools.”
“I’m Catholic and I’m pro-choice.” No one doubts that many people consider themselves both Catholic and supportive of legal (and constitutionalized, and sometimes even subsidized) abortion. Our article would not exist in the first place were it not directed against the coherence and soundness of this position. Re-asserting its existence is not even a glancing blow against the pro-life argument.
“The cells I scrape off my arm are also human life. This is an equivocation on terms.” No, the equivocation is yours. Those cells are not “a new and distinct member of the species Homo sapiens,” the human beings we argued deserve protection. Those beings are organisms in their own right, not functional parts of other organisms.