The key authority in a school is the principal. They are are ones that shape the learning culture. For an Evangelist to be successful, they need to have the explicit support of their school leader.
The authority for the principal flows from the superintendent. They, in turn, receive their authority from the school board and the state's education department.
The permission to innovate is critical. If that permission does not flow down the authority chain, down to the teacher in a classroom, then it is extremely difficult to take the risks required for innovation.
Sometimes this permission, however, is not explicit, but implicit. That is, that innovation is allowed, not embraced and celebrated. In these situations, the path of transformation is still possible, it just will be slower and its leaders need to be more resilient.
New thought: should we call "Authorities" "Permitters"