Someone correct me if my source is wrong, but it was explained to me that federal law states that you cannot 'discharge' a firearm in or on school property, does not make reference to 'carrying' a firearm on school property. My source if a family member who worked for a school district and hosts CCW classes back home. This info was given to him by a retired LEO who instructs the classes. Any merit it? (I know that many states have put in effect laws that tighten up where the feds left off, but...)
In some cases (like here in Lincoln) the school board/school district can (and has) write a student policy and an employee policy that does not allow weapons anywhere on school property, even in a vehicle... therefore even transporting in accordance with federal law can get a student/employee expelled or fired.