Suspected Kansas shooter Frazier Glenn Cross was described as a libertarian, defined in the article as someone in favor of smaller government. He was also described as being virulently anti-immigration, a self-described racist and an anti-Semite.
While libertarians generally favor the smallest government possible, this is because the philosophy maximizes individual freedom for everyone, including immigrants, African Americans and Jews.
In the libertarian perspective, the only legitimate role of government is to protect individual liberty from those who would destroy it, such as Cross with his violent actions.
Please do not lump libertarians in with right-wing crazies such as this man; it badly misrepresents the views of many Americans, including the country's Founding Fathers.