POLITICS MAKES FOR strange bedfellows, but Senate Republicans doing the bidding of teachers’ unions is particularly unexpected. That, though, is what happened when an important provision on teacher evaluations was knocked out of a proposed rewrite of No Child Left Behind (NCLB). Given that the legislation had already abandoned meaningful student achievement targets, the latest change renders the bill a non-starter.

The Senate’s education committee is set to begin work Wednesday on a proposed reauthorization of the Elementary and Secondary Education Act, known in its latest incarnation as No Child Left Behind. Sen. Tom Harkin, the Iowa Democrat who chairs the committee, released last week an 865-page bill that in its latest iteration is supported by Sens. Mike Enzi (R-Wyo.) and Lamar Alexander (R-Tenn.) No Child Left Behind needs an overhaul, and this attempt has commendable aspects, including a requirement that states set college- and career-readiness standards, the retention of reform initiatives such as Race to the Top and Promise Neighborhoods, and a federal focus on worst-performing schools.

But those positive components can’t compensate for the proposal’s retreat from accountability provisions, a retreat that rightly came under fire from civil rights and education-reform advocates. It’s a foregone conclusion that NCLB’s strict yardstick of Adequate Yearly Progress to measure student achievement will be scrapped, but the bill’s allowing states merely to show “continuous improvement” in student outcomes is a far cry from what is needed to ensure accountability for poor and minority students. One critic likened it to paying a kitchen contractor who never finishes the renovation as long as he promises incremental progress. Mr. Harkin said he wanted achievement targets in the bill but backed off in order to get support from Republicans, who are wary of any federal role in school policy.

The same impulse led to Mr. Harkin’s agreement over the weekend to drop a requirement that states develop teacher and principal evaluation systems. States and districts would have had great leeway in devising the details of the systems, but not enough to satisfy many Republicans. The National Education Association, meanwhile, doesn’t like using student achievement to measure teacher effectiveness, which is a bit like measuring race car drivers by everything except how fast they go. So the NEA and GOP forged their alliance, and the provision was dropped. Mr. Alexander told us that states would be more successful in setting up teacher-evaluation systems without a lot of mandates from the federal government and that the bill contains incentives for states to undertake evaluation reform. “I am no friend of the NEA and they are no friend of mine,” Mr. Alexander told us.

The Obama administration is right to resist proposals that, under the mantle of bipartisanship, retreat from reform. Schools should be held accountable for improving student academic results, and teachers should be evaluated based on how well they teach. It’s sad that either one of those propositions remains controversial.