Nonsense. Go into any public school system and find an honest Principal. He/she will tell you the biggest problem they have is the union protecting abusive and incompetent teachers. You cannot get rid of a teacher once they have tenure, and far too many of them choose to just dial it in until they can qualify for their generous pension.
State and federal government is a huge problem, but it is not the biggest problem facing K-12 public schools.
You don't know what you're talking about. It's obvious you're just cutting/pasting garbage you've read elsewhere. What problems are you referring to? The lack of students learning? Violence in the schools?
First of all, go find an "honest" principal. Nowadays, they are totally political, dancing to the tune pressed upon them by politicians sticking their nose where it doesn't belong, in a field they generally know nothing about. These politicians have bought lock, stock, and barrel some crazy untested left wing teaching methodology sold to them by some ivory tower libtard whose only experience with such a program was with blond, blue-eyed darlings whose parents supported and supervised their learning. This program, such Commie Core, is dictated as "what will be" to principals, generally without any professional input from people with actual educator experience. The program is then dictated as "what will be" to the teachers, who have no choice but to implement it.
Coupled with this is the new trend of not allowing teachers to discipline students in a normal teacherly fashion. Everything is labeled "corporal punishment", from asking a student to put their cell phone away to telling them to be quiet and take out their textbook. Without discipline, you cannot have effective learning in a classroom because there will be too many distractions. And the students know it.
So the teacher, who has labored over crafting their lesson for a couple hours, is teaching to a bunch of kids who could care less--they're too busy playing with their cell phones, talking, walking the halls instead of attending class. These same students fail to turn in assigned homework, fail to take responsibility to study even for announced tests, constantly disrupt the class, and often fling insults, verbal or physical, at the teacher. You can imagine the abysmal grades resulting from this. Who is blamed? The teacher, of course. It's always the teacher.
Administrators change grades without even consulting the teacher. Teachers are called in for disciplinary meetings originating in complaints from snowflakes who could not bear to be told to put away their phone or cease talking during a lesson. The lax disciplinary atmosphere dictated by "progressive" administrators pretty much destroys any hope of being able to conduct a class without disruption.
Teachers are still held, nonetheless, to passing rates near impossible to attain under such conditions. There are such budget cuts to schools that it is impossible to get materials xeroxed, have pens or pencils, there are severe shortages of paper (I've seen teachers carrying around reams of copy paper with their names written on the package), shortages of textbooks, no working computers available for teachers to do work, software programs which don't work but which cost thousands of dollars, students being allowed to substitute online "learning" programs for classroom work, etc.
But of course, this is all the fault of the teachers and the union. The reality is that the unions are vampiric, sucking over a thousand dollars a year from teachers' salaries yet being totally in cahoots with the school systems to victimize their teachers with ambush observations (often out of license), false accusations, loss of days traditionally given off, longer hours, oversized classes, etc. which are never addressed. Instead, the union devotes teacher dues monies to promoting social justice causes and contributing (without input from teachers) to the political party of THEIR choice. Although a very healthy percentage of NYC teachers, for example, are not democrats, their union saw fit to donate 98% of their political money to the democrat party, to the Clinton foundation, and to innumerable other shady causes.
So being robbed of their autonomy in the classroom to teach their subject the way years of experience informs them it should be taught, being forced to teach in absolutely weird ways which actually impede understanding, having their students as their actual "bosses" who dictate what can and cannot be said or done in the classroom or they'll gin up some fake accusations threatening the teacher, being unable to impose normal discipline in their classroom, having to compete with cellphones the administration refuses to ban, being forced to violate the contract without any support from the union, having to spend hundreds of their own dollars in the classroom to make up for the severe lack of materials, etc., it is only logical that teachers are leaving the hell teaching has become. It is the mark of a healthy logical mind that one would not want to remain under the now constant lash. Is it a surprise that severe teacher shortages are developing and that some areas cannot even attract teachers with bonuses?
It's all the teachers' fault, though. Just keep repeating that. Won't make it true.
I don't see any of that where I teach.