Obviously this is a power that can be abused (but really, any power can be abused). There are drug addicts and students who come to cause disorder and trouble, and interrupt the educational process.
Troublemaking students should be expelled but not on the first count (unless it is serious enough). That is my two cents.
I think that if a school administration feels that a student is posing a threat to the safety of another student or staff member then they should have the authority to be able to suspend or expel that student, a school should be a place where everyone feels safe and those who try to disrupt that peace must be dealt with.
Expelling students is not the answer to curbing school violence. When a student is expelled from school, he (or she) falls farther and farther behind in his work, which only makes him more trouble when he returns. A better option is alternative classrooms, where students are sent when they cannot make it in their regular classrooms. In the alternative classrooms, students are led to figure out why they are having difficulty, what can be done about it, and then helped to fix the problem. Many students have been helped with this type of approach when, had they been simply expelled, they might have eventually dropped out and perhaps never have lived up to their potential. Expelling students and sending them home is rarely a good alternative. Many times the home is the reason for the problems the student is having in the first place. Schools need to be places where even the bad kids get a chance to improve.
I do not believe schools should have more leeway in expelling students in order to curb school violence. Schools already have quite a bit of power when it comes to expelling students, however they are in place to provide an education and that can't be done when the student isn't in class. Schools need to handle the problems and study ways to better handle them. They shouldn't just guess an action will work and try it with massive failure.
No, schools do not need more leeway in expelling. When you expel a student, they then have nothing to do but get in more trouble. We need to move away from the "expulsion" mind set because it serves no purpose - all you're doing is moving the violence from the school to the street.
I think there are many ways to curb school violence, but expulsion should only be a choice if it happens frequently with one student. I think better environments need to be created in these schools, so children can thrive and violence is at the back of their minds, if anywhere at all.