A high school student in San Antonio Texas who brought an unloaded handgun to school was charged with violating the gun free school zones act of 1990. The student challenged the charge claiming that congress did not have the power to override state law within public schools. In 1995 case United States v. Lopez, the Supreme Court ruled that congress did not have the power to regulate public schools. Instead, the court found that that power belonged to individual states.

Explain which constitutional principle this scenario illustrates. What evidence led you to that conclusion?