The next time someone asks you if or why you don't support a woman's right to choose, don't answer the question.  Try saying something like this:

"I can't help thinking that when people ask me that, they're not being honest, but rather are trying to set some kind of rhetorical trap so they can use any answer I give them to prop up either the assertion that they have support for abortion amongst the hypocrites who claim to be pro-life but really don't want to see abortion go away, or the assertion that we're really the villains in some Marxist morality play who want to keep women barefoot, pregnant, and away from the polls.  But keep in mind that abortion to us is a legal issue above and beyond any legal considerations for which women are the sole subject.  You might as well be a plantation owner in 1860 asking an abolitionist whether or not he supports the owner's right to choose to employ the labor of slaves or free men."  

Sure, they could make the argument that the plantation owner shouldn't have to bend to the whims of Washington, but whatever evidence currently supports that argument takes a back seat to the grave injustice that was chattel slavery, and they know it.

It is a fact that slavery, as an institution, was first and most thoroughly stamped out of civilization, and most effectively remains at bay, by Christian nations.

This is not obvious from the New Testament, with Paul even admonishing slaves to be good servants and masters to treat their slaves as brothers; but at the same time these notions were planted as the seeds of slavery's demise.

There are some who may wish to point out that in the American Civil War, many Christians fought for the Confederacy, and so either formally supported retaining slavery or at least were willing to tolerate it even though the tide of history had shown that a nation supported by a class of imposed servitude was not inevitable.

Disregard these people.  They are trolls.

If they honestly don't see the difference, remind them of how the rest of the world did not oppose slavery in some form or other, and how even in the now-free Christian nations, it took time to win hearts and change laws and the ways of living.

If their only criticism is that, compared to a world full of slavery, only Christians abolished the practice, but had to struggle to do so, then what point do they think they can make instead?  Do they have any position to stand on but the anonymized residue of Christian values?