Ron Paul is airing an anti-abortion ad in Iowa in the hopes of courting social conservatives ahead of the first caucus in the nation.

In the ad, Paul contrasts two experiences he had as an obstetrician-gynecologist. In the first, he says, he watched doctors perform a late-term abortion and put the fetus in a garbage can in the corner. Just a little while later, he watched those same doctors scramble to save a premature baby.

Who are we to decide that we can pick and throw one away and pick up and struggle to save the other ones? he asks. The whole notion of life not being valuable is something I am not able to accept.

Abortion is a sticky subject for libertarians, whose firm belief in individual freedom tends to lead them to oppose government restrictions on a woman's right to have an abortion. But other libertarians, like Paul, argue that when a woman has an abortion, she is actually violating the fetus's right to individual freedom.

Unless we resolve this and understand that life is precious and we must protect life, we can't protect liberty, Paul says in the ad.

The ad began airing on Friday on TV stations in Iowa, where the first-in-the-nation caucus has traditionally rested to a large extent on socially conservative voters. It will also air on radio stations in New Hampshire, Nevada and South Carolina, which will hold their primaries and caucuses right after Iowa's.

The latest Public Policy Polling survey in Iowa showed Herman Cain with 30 percent of the vote, Mitt Romney with 22 percent and Paul in third place with 10 percent.