Each state has their own definition of bullying (if any).
That is one of the many problems with this problem: How to define it.
Extremes are easy to define
Kid repeatably getting the crap beaten out of him would probably be considered bullying.
Kid choosing not to play with another kid would probably not be considered bullying.
Where is the "line" between the two extremes?
If you are going to have a policy or a law prohibiting bullying, you have to have a standard where an authority can determine that
This is bullying.
That is not.
A very very hard issue to solve.
A bully is a lot like art. You know it when you see it, but it can be hard to define.