The author does here what he condemns in the article. He does use the the perjorative sounding "anti-abortion", and put "pro-life" in quotes, but he never really says why the analogy of abortionism to Naziism is improper. Sometimes such analogies are entirely valid, and comparison of mass abortionist killings of babies with certain aspects of the mass murders that the Nazis perpetrated is one of those instances.
Cordially,
OTOH, there is no doubt that Abortion is like the holocaust in the sense that the comparison is made in. One group, the unborn, has been targeted for destruction mostly for out of a selfish desire of a more powerful group to have "living space" in a lifestyle sense. Even the numbers are roughly the same. I think about 1/3 the Jews in Europe were slaughtered. About 1/3 preganancies in the USA ended in abortion at its height. It is not much off of that now.
Conclusion: Some people really DO act like Nazis in one sense or another. The abortion crowd is among them.