Cardinal George has drawn a parallel between slavery and abortion here.

Slave owners once argued that they had the right to choose to own slaves or not. The federal government, they argued, should not only allow them to choose, but should enshrine in law their ‘freedom of choice.’ The government did this in the Dred Scott decision–deciding that the federal government had no power to take away the choice of individuals to own slaves.
Then in 1865 the government changed its mind, and in the thirteenth amendment abolished slavery and in the fourteenth guaranteed citizenship regardless of race.
There must have been plenty of people back then who said, “I’m personally against slavery, but I think it is up to the individual.” 
Let’s be clear. Americans in the 1850s who were ‘pro choice’ were actually pro slavery. 
By not being opposed to evil you endorse evil. Likewise those who say, “Nobody is pro abortion. We’re just pro choice” are guilty of self deception. They are indeed pro abortion–just as much as the pro choice lobby for slavery was in favor of slavery. If they really were against abortion they would work to get rid of it–even if that meant denying slave owners their ‘freedom of choice.’