[Principled]

But, in my school district, more than 25% of the teachers are not highly qualified. (i.e. they are not certfified to teach what they are teaching!)

No. What happened is that the feds changed their definition of what it means to be certified.

So it isn't the case that "not highly qualified" teachers have been teaching all along. They just changed to definition to make it seem like they're trying to up standards.
They're not.

[Swing_Thought]

In VA, highly qualified simply means that the teacher is certified to teach the subject. Neither classroom experience, advanced degrees, or any other measure of a teacher's expertise is part of the equation.

Nobody changed the definition or made it more stringent. In fact, just the opposite is the case. The usage of the term highly qualified leads the layman to think it means more than it does.