You blame the teachers unions as any right-wing individual would. The fact that evidence does not support this is irrelevant.

FACT: Teaching unions in the US are weak and ineffective. They are unable to get decent salaries compared to other top countries and have been less successful than their equivalents in other countries at getting progress on just about every issue they've had in bargaining.

FACT: The US education system is weak and ineffective. It is ranked poorly and continues to decline.

FACT: The vast majority of successful educations systems have strong unions and highly paid teachers.

You can't expect to get good science teachers on $20,000-$40,000/year. If one has to do an undergraduate degree to get into a teaching program, and an additional year in a teaching program to be qualified, then at many American Universities you're talking about spending $100,000 and 5 years of your life doing this. Jobs from the BSc average about $44,000 and that's with 1 less year of education and 1 less year of tuition fees. In Canada, with full professional qualifications (BSc, BEd, MSc or MEd, up to date on all professional training requirements plus certain level of job experience) a teacher can earn $80,000/year (lets say about $75,000 US since the exchange rate fluctuates). The entry level position earns comparable to what one can get on a 5 year university education, and thus is competitive in the marketplace, and its more practical to go into teaching because the cost of university is much lower (The University of Toronto is ranked anywhere between 15th and 43rd in the World and costs approximately $6000/year for Canadian students to attend).

Countries like Sweden, Finland and Norway are famous for incredibly high literacy rates (near 100%) and strong education programs, all of them also have strong teachers unions, and good salaries.

The fact is Americans like their low taxes at the expense of good programs, and as long as you continue to do so your education program will be bad. When you try and put money on the problem it happens in effective ways based on political commitments and pork-barrel spending, programs which educators would tell you are doomed from the start, and then when they fail you take it as an excuse not to try. Anything for lower taxes seems to carry the day.