I haven't read all the posts, but I can assure you that in my district (I'm an administrator in a charter school) that isn't true at all. Admissions is by strict lottery. In the beginning the only exception to this rule was for siblings. Recently they've decided that people who were involved in the founding of the school (our founding board chair who has donated many hours of time to our school didn't get his child in the PreK lottery) and staff members can also have precedence, but this is a new rule.
We can not ask questions about disability on our applications, we have to take all students regardless of their history, disability, whether they were expelled from their previous school etc . . . We get far more students with disabilities (and do a fantastic job with them) than the regular public school. We also get children who are years behind because they've been failed by the public school and have 7 months to catch them up before we're judged on whether or not they're on grade level.
Furthermore, we can't "just kick a kid out". As a single school district we're too small to have the wide range of programming that the public schools have. If a child is deemed to need a special class for children with severe autism, or emotional disturbance or whatever, then we have to either program for them in our school, or go through the same process the public schools would go through to prove that they don't have a slot for them. That is to say, the public school system would have to prove that none of their many self contained special ed classes are appropriate, while we have to prove that we can't do the same things they do without self-contained special ed options. It's about a 6 month process and involves proving that you've done every single thing that you could be reasonably expected to do, such as hiring a one on one aide, modifying the child's schedule, bringing in specialists and therapists etc . . .
In my school we spend an incredible amount of time and energy on special ed, and we do it well. We have a special educator for every 2 classes, an ESL specialist for every 4, and an array of therapists and evaluators. We have professional development targeted towards helping general education teachers work with children with special needs, and plan lessons that reach everyone.
And we do this on what is effectively less money. Charter schools in my city get the exact same per pupil funding as the public schools. The difference is that public schools are located in big buildings on big pieces of land that are essentially given to them free, because the mortgage was paid off years ago, if a public school closes and we want to rent one of those buildings we have to pay "market rent", out of the same budget that they have.
To be clear, I'm not complaining. What we do is at my school is public education at it's best, and we have the test scores to prove it. We're proud to serve a wide range of kids and actively recruit to make sure that stays true. It bothers me, however, when someone discounts our results by stating that we don't have the same challenges as the public schools. It's excuse making of the worst kind, justifying crummy performance by public schools by yet again blaming it on the kids.