The foundation of Libertarianism and the ideals of the founders were the principles of self ownership. The ethical standards from group to group and individual to individual is as dramatically different as the cultural and racial make-up of our country. To assume that all people are going to come to any common agreement on social policy or should be forced to comply with such laws is impractical and unnecessarily divisive.
One of the more common examples of the intrusion of moral law upon our society is the war on drugs. The cost of this "war" contrived by the government is estimated as over 1 trillion dollars, the effects of which has not decreased drug use by any measurable example. What has decreased is the common freedoms and civil liberties that the citizens of this country once enjoyed, as lawmakers continually employ more intrusions upon our personal property for the sake of crime prevention and drug abolition. Ironically, this comes at the expense of the taxpayer, as property taxes and income taxes- his personal property and productive capacity- are what is used to fund this continued failure. This also diminishes the focus of the police force on real violent criminals, as they arrest and overload our prisons with nonviolent drug offenders. The 18th amendment to the Constitution was repealed for just that reason, as the only prosperity from such laws comes from the black market and criminal syndicates.
The central theme of self ownership concludes that one may do unto one's body what one sees fit assuming this action does not harm or violate the rights of another. Even if we regard abortion as ethically reprehensible, Libertarianism is only concerned with governmental policy and intrusion into the lives of individual choice. The subject of abortion from a Libertarian stance would then conclude that abortion would be deemed the choice of the individual until it conclusively violates the rights of the unborn.
In addition, making an act illegal, as we clearly showed in the drug example, does not stop or even decrease an activity, but certainly makes it more dangerous. Abortions would become a life threatening black market activity for young women that would inevitably erase the safer, more controlled situation between doctor and patient. As with any moral hazard any society faces, it is always better to educate individuals on the realities of their choices with truth and facts then to simply dictate morality with legislation.
The 10th Amendment states that:
"The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people."
This amendment states that the federal government shall not interfere in the practices of the individual states or impede state sovereignty, outside of the Constitution. And that its constitutional authority is limited, therefore, to the Articles and Amendments of the Constitution. Any expanded authority would have to include additional amendments, and that any legislation contrived outside of the constitution will be deemed unconstitutional. Any legislation brought forth on the congressional floor containing social policy and/or social limitations not covered by the amendments must then be considered unconstitutional and outside the scope of the legislative body.
Limited government and individual rights promotes personal responsibility.