I think all of the teachers are hired by the 7 member school board. And if 4 of the members (majority) agree that person is hired.
This is why we have so much Nepotism in our school district.
I think the school board should have a board consisting of Principal's or other educators interview teacher candidates and recommend the best to the school board for the final decision based of this these interviews.
This would prevent persons being hired based on connections or where they live or sports etc. and better insure those most qualified to teach.