The piece of recent government legislation which has had the worst effect on public schools is the NCLB act.
Is the NCLB act the only factor which contributes to the continuing downward spiral of public schools? Of course it isn't. It is, however, the ONLY one which is a federal mandate. If you want to see the complete and utter breakdown of the public school system, envision what would happen if our government were to federalize solutions to the other factors you cited. Liberal indoctrination, powerful unions, the breakdown of traditional families...these are all factors which are effecting our schools, that is not a dispute. Those factors can be addressed and even controlled at a local or state level. The NCLB is the worst because it is federal.
So, at a local or state level you are seeing the teacher union problems successfully addressed?
You want I should split hairs? Oy!
I am not asking anyone to split hairs, merely to modulate their rhetoric. Again, out of my list the NCLB would not even make my top five, nor would it make yours, I presume.
Is the federal government getting involved in public schools a great idea that I support? No. Is it worthy of "single, worst" thing to happen? Nah, not even in the top 10.
I said in recent memory.
Oy veh!