I think most people who say that "abortion is murder" are actually speaking hyperbolically; if you ask them "so does that mean that every woman who has had an abortion ought to be doing twenty-to-life for infanticide?" most will start hemming and hawing. I think the proportion of Americans who want abortion to be treated exactly like murder, as it is in El Salvador (http://www.nytimes.com/2006/04/09/magazine/09abortion.html), is extremely small.