Honestly, I think kids should speak politely to adults and that teachers deserve at least that much simply because they are adults and authoritly figures and human beings, but that's not really a respect thing, it's just plain old manners.
Everyone deserves to be treated politely until they lose that right because of thier own actions. However I don't think anyone automatically deserves respect. Respect is given to those whom you admire and feel deserve special consideration. You earn respect through your actions and words. I respect the law, but if an officer is misusing his power I will not respect him no matter what uniform he wears. I respect education, but being a former teacher I saw too many educators who were ugly to thier students and did only enough work to get to the next vacation, and didn't deserve any respect.
I speak politely to everyone, but I don't have to respect you to be polite.