the people who push vouchers generally do so because they WANT to suck funds from public education and have us pay for their kids' parochial school and destroy what they consider 'secular' education.
and you're right of course, public schools have no choice about the kids they take...
Not the people I know.
I'm for vouchers. Not because I want to destroy public education, but because by and large the state and local governments refuse to change the way public education is handled.
And you kind of touched on it. Public schools have no choice about the kids they take. Private schools do.
When I was in middle and high school, the degenerates and habitual troublemakers were shipped to their own school. Can't do that anymore. I can see why people would have a problem with doing it, but putting them back in the general population of a school doesn't work either. So now the troublemakers continue to disturb things, and the teachers really can't do a damn thing about it anymore. At least in the two school districts that I am familiar with. Brings the whole thing down. The teacher has to teach to the lowest common denominator, and education suffers.
In my daughter's private school, you only get so many discipline warnings and then you're out. For good. And the teachers expect the students to keep up with the curriculum, not the other way around.
Anecdote time: My daughter went to public school for kindergarten and first grade. During her first grade year there were groups of kids that you could tell were just plain raising themselves, with no parental involvement. One of the kids from that group went around calling all the caucasian girls in his class (my daughter included) "fucking cracker sluts." First freaking grade, and I don't think he even knew what the terms meant. He had obviously heard it from older brothers or sisters. Although we went to the administration, the school couldn't really do anything because the parents refuse to be involved at any level in these kids lives. And the parents expected the school to essentially be a babysitter. Add to this that while my first grader was going to this school, she tried to emulate the "cool" kids in her class, with the finger wagging, hand on hip "oh no I AIN'T gonna do what you say" disrespect for adults.
It was then that I decided that no matter what the cost, my children would not be going to public school while this crap was going on. This past year in private school, my daughter's attitude has changed dramatically for the better, the worst the "problem kids" do are skip lunch lines or whisper in class, and she is actually having to WORK to learn, as the teacher is stretching her capabilities.
Change the tail wagging the dog in public education in discipline and curriculum, and I would send my kids back to public schools in a heartbeat because I do believe that the diversity they would encounter there would help them grow tremendously. I don't see that happening any time soon though.