Even though the weight of the argument is strongly on the pro-life side, the pro-choice side has until now won politically. This is because liberals understand that abortion-on-demand is the debris of the sexual revolution. If you are going to have sexual promiscuity, then there are going to be mistakes, and many women are going to get pregnant without wanting to do so. For them, the fetus becomes what one feminist writer termed "an uninvited guest."
As long as the fetus occupies the woman's womb, liberals view it as an enemy of female autonomy. Thus liberalism is willing to grant to the woman full control over the life of the fetus, even to the point of allowing her to kill it. No other liberal principle, not equality, not compassion, is permitted to get in the way of the principle of autonomy.
The abortion issue reveals the bloody essence of modern liberalism. In fact, it is the one issue on which liberals rarely yield. Being pro-choice is a litmus test for nomination to high office in the Democratic Party. Liberals as a group seem to oppose any restriction of abortion. They don't want laws that regulate late-term abortion. Many liberals object to parental notification laws that would notify the parents if a minor seeks to have an abortion. We see from their recent reaction that even partial birth abortion is acceptable to the Democratic presidential contenders, like Obama and Hillary. One may say that in the church of modern liberalism, abortion has become a sacrament.
What, then, is the challenge facing the pro-life movement? It is the same challenge that Lincoln faced: to build popular consent for the restriction and ultimately the ending of abortions. Right now the pro-life movement does not enjoy the support of the American people to do this. Neither, by the way, did Lincoln have a national mandate to end slavery. It is highly significant that Lincoln was not an abolitionist. He was resolutely anti-slavery in principle, but his political campaign focused on the issue of curtailing the spread of slavery to the territories.
In my view the pro-life movement at this point should focus on seeking to reduce the number of abortions. At times this will require political and legal fights, at times it will require education and the establishment of alternatives to abortion, such as adoption centers. Unfortunately such measures are sometimes opposed by so-called hardliners in the pro-life movement. These hardliners are fools. They want to outlaw all abortions, and so they refuse to settle for stopping some abortions, with the consequence that they end up preventing no abortions. These folks should learn some lessons from Abraham Lincoln.