Considering the fact that libertarians stand in favor of limited government, one can extrapolate that libertarianism leads to anarchy. Having a libertarian President or majority in congress would radically change the country in ways that would make our founding fathers cry. All market regulations would be nonexistent, including child labor laws. We would all be forced to labor for too many hours per week at the minimum wage of $1 per day in the manufacturing plants that would dominate the landscape. Pollution would be viewed favorably, and we would all become sickly from contamination in our food and water supply very quickly. Anti-government sentiment fueled by ignorance would lead to a total dissolving of the federal governments, and state governments would be solely responsible for police and defense. Taxation would be too low to support either group, and anarchist post-apocalyptic gangs would run rampant stealing and raping until either China or Russia decided to bomb us and invade.
But at least American business would be on top.