From a moral philosophical viewpoint. The reader who sent the link remarks:

It does argue that the “natural law”
argument against abortion is in fact a religious argument, not a
secular argument — a distinction that makes more difficult to justify,
for example, the attempt by Bishop Burke to effectively excommunicate
Catholic public officials for refusing to support the bishops’ effort
to prohibit abortion.

From my work many years ago with those from other denominations, I
know many individuals of good faith who see any push for antiabortion
legislation as an effort to impose a specifically Catholic moral
teaching into a society that is supposed not to favor one religious
view over another. They see the invocation of natural law — that any
moral person can see that abortion is The Very Worst Thing without
recourse to a specific religious perspective — as itself a religious
perspective, and disingenuous to boot. They thus see no place for such
a view in public policymaking, just as they see no place for, as an
example of something that the bishops would probably oppose, the calls
for school prayer from the Protestant Christian right.