Teachers unions remain the Goliath to the school reformers’ David. That was the lesson from votes in Idaho and Indiana, where unions successfully took on or took out Republican school superintendents.

In Idaho, three laws associated with Tom Luna, the state superintendent of public instruction, were repealed by referendum, turning back the clock on efforts to phase out teacher tenure, to link pay increases to performance and to expand online learning. In Indiana, Tony Bennett, often called the darling of the national education- reform movement, was fired from his job, despite outspending his little-known, union-backed opponent by 4-to-1. Bennett had been an aggressive advocate of vouchers and charter schools, and had called for stronger state control of struggling schools.

In hindsight, the losses shouldn’t have been surprising. Even when reformers outspend their opponents, the unions easily out-organize them.

What lessons should school reformers take from the Indiana and Idaho experiences? Should we adjust our policies? Our tone? Our political tactics? The answer: All three.

First, it’s time to stop angering suburban parents and teachers by subjecting their schools to changes they don’t want or need. It’s not that suburban schools are perfect – their performance lags behind that of our international competitors, too. But the policies required for these schools to go from good to great are different from those needed to get urban schools from dismal to decent.

Top-down, one-size-fits-all efforts such as formulaic teacher evaluations tend to overemphasize the high-stakes testing that can take the joy out of learning. Parents and teachers in richer areas typically hate this pressure. Reformers can’t put together winning political coalitions if they lose the suburbs. When it comes to middle-class schools, reformers should follow the doctors’ dictum: First, do no harm.

Second, we must renew efforts to show respect for teachers. This can be complicated: Many schools face a teacher-quality crisis after years of low professional-entry standards and lax accountability. At the same time, most teachers are dedicated and hardworking. We need to stress that bad teachers are rare but devastating and that efforts to weed them out will lift the entire profession. Any rhetoric that implies that most or even many teachers are incompetent or uncommitted to children needs to be scrapped.

Finally, proponents have to get better at political organizing, especially the ground game. The only way to defeat an army of determined educators is with a larger army of equally determined parents. The advocates of school vouchers and home-schooling have learned this lesson and can bring busloads of supporters to state capitols on remarkably short notice.

That has been critical to the success of school choice in Florida, for example, where 5,000 people, including low-income parents, turned out for a 2010 march in Tallahassee. The broader movement needs to head toward identifying parent activists and engaging them in the fight.

Victory over the long run can be achieved only if we learn the right lessons from defeat. By aiming our efforts at the schools with the gravest problems, changing our tone and improving our organizing tactics, we can keep moving in the right direction.