"Indeed, evidence suggests that quality of teaching is the most important non-demographic contributor to student learning."
Okay, but what has been most responsible over the last generation for changing the demographics of public school students? The answer is the elite conventional wisdom that celebrated mass immigration and denounced immigration skeptics as racists. (Matt, for example, wants to import another 165,000,000 immigrants.)
Bashing teachers (a huge group of people who are, not surprisingly, pretty average and thus, on the whole, non-miracle workers) is just the inevitable reaction of ruling class elites as they attempt to elude responsibility for their immigration policies by blaming the teachers for not eliminating the racial gaps in student achievement. If you don't believe that teachers can wholly eliminate racial gaps caused by "the soft bigotry of low expectations," then, obviously, you are a racist. So, don't blame George W. Bush or Ted Kennedy or Matthew Yglesias for America's immigration policies, blame teachers for being bigots.
The sanctity of education reform is a by-product of the sanctity of diversity. Since we all know that diversity is the highest social value, therefore, increasing diversity by allowing in tens of millions of illegal immigrants and their descendants is an unquestionable good.
Unfortunately, the test scores don't support that.
So, "all we have to do is fix the schools." That must be easy, because if it's not easy, that would call into question the goodness of diversity, and that is unquestionable.