I'd say initially a teacher should be respected by his charges.What happens thereafter will depend on whether the teacher can maintain that respect,according to what happens in and outside the classroom.I say outside as well as in the classroom because a teacher who is accidentally observed by a student of his (or hers) behaving in a manner unbefitting of the profession while among the general public will lose respect.For example,behaving in a drunken manner at a restaurant in the company of a lady of the night would be a bad thing.Respect needn't be earned by teachers,but unfortunately it is lost by some of them for one reason or another.