Are you or anyone in your family a teacher? And what is the purpose of a teacher's union? Are teachers measured on performance? Can they be fired? Do they work 2,080 hours a years less 10 holidays and two weeks vacation?
Teachers' unions serve to even out the natural pay and benefits differences that would occur between pay, middleclass and upscale districts.
Since many/most have post-grad degrees they are fairly well compensated.
That said, they are pretty much doomed since many districts can no longer afford public education.
Yes, I'm one of the few people in my family not to be a teacher. And teachers are measured on performance...they get regular reviews, and can lose their jobs quite easily. One of my friends lost his job as a teacher for having 2 marks on his record...one mark from a student who complained that he didn't wear a wedding band even though he was married (a personal choice he and his wife of 20-some odd years had made) and the second mark from a student who whined about him having the American flag up in the room (which I always thought was standard in every classroom in the country...least it was in my day, probably yours too).
As for the amount of time they work, you realize that in most districts, teachers have one of two options...they can get their full paychecks during the school year, or they can have it cut down and continue to recieve pay during the summer. It still doesn't change the fact that a great number of teachers must find a second job during the summer, and sometimes even during the school year, especially those who are just begining and are single.
As for the purpose of the teachers unions, admittedly, they are now just becoming lobbying organizations on a national level that are doing very little to improve anything for their members, but at the local level, they do fight for better wages, but more importantly, increased resources for the classroom so the teachers don't have to pay out of pocket for things like books.