Former L.A. Mayor Antonio Villaraigosa: Why Are Teachers Unions So Opposed to Change? As a former union leader and a lifelong Democrat, I am deeply troubled by their rhetoric and strategy.

The Wall Street Journal has former L.A. Mayor Antonio Villaraigosa take on the teachers unions:

As a former union leader and a lifelong Democrat who supports collective bargaining, I am deeply troubled by the rhetoric and strategy we heard at both national conventions. They attacked an administration in Washington that helped protect 400,000 teaching jobs during the recession, has actively promoted labor-management collaboration and has empowered classroom teachers to help shape policy.

Others are in full-throated denial over the recent California court ruling striking down the state's public-school teacher tenure and seniority laws—despite compelling evidence that it is nearly impossible to remove ineffective teachers from the classroom and that the least effective teachers disproportionately end up in classrooms with low-income children. We should be working together to fix the problem rather than defending a broken system.

Most say they are for accountability yet they dismiss measures of a teacher's effectiveness as a "sham" and insist that standardized tests are "invalid" and "unreliable." Let's be clear. Testing isn't teaching, and school districts that devote too much time to testing and test prep are doing a disservice to children. But parents and taxpayers need to know if children are learning. Without a test, too many children will slip through the cracks and too many ineffective teachers will remain in the system.

At the same time, we need to know which teachers are really excellent so they can help their colleagues improve and which ones need more support to get better. Finally, we need to identify the small percentage who lack the passion or capacity to teach and counsel them out of the field. That's not an indictment of the teaching profession nor is it antiunion. It's a fact of life in every field. Countless teachers and many union leaders agree with these common-sense measures, yet at their conventions, the most regressive voices are amplified while the reasonable, fair-minded voices aren't heard.

The great moments of public education.