There are people at the national or state (ie political folks) who are usually the driving force behind it and it's for exactly what I said it's for from the Repub side. Of course Dems fight against it primarily for the same reason though an obviously opposite outcome. It's all about votes and money and power to them.
On the personal/individual level of course there are people who just want the best education for their kids, but it's been my experience those aren't the main (numbers) force involved. Some really do just want the best possible education for their children and I commend them and we all know people who we can use as examples. The most numbers IMO are those who just want the babysitting and social club and next generation of local and regional leaders, ie the social elite of a particular area
and other similar types of perks that cajun mentioned, and as long as little Johnny and little Mary get good grades and their share of accolades the parents just assume they're getting a good education.
There are always examples of good people just wanting the best (I mean the actual best, not just the easiest) for their kids, but I have not seen nearly as many of those as I have the other kind. Bedell and I used to have this conversation a lot ((I miss Bedell by the way) if a person's experiences show examples of one type or another that's usually the ones we remember and the ones we apply to such questions and discussions.
It's like the lazy, incompetent "just doing it for the power trip and the paycheck" teachers you hear used as examples for what's wrong with our education system. We all know at least a couple of those, but that really isn't how most of them are. The useless ones should be gotten rid of ASAP but they usually have some kind of family or other "connections" in the community, which is often why they got their job in the first place. If we really looked at what most teachers do on most days we'd see one of the best and most dedicated and selfless group of professionals in this country. Now the parents, and the kids, and the administrators, that's a whole other can of worms.