In school districts around the country, the Bush administration's centerpiece education law is beginning to emerge as an issue at the bargaining table.
In Sandy's 4,200-student Oregon Trail District, where the strike is in its third week, teachers are afraid they will be replaced, transferred or otherwise penalized if they, their students or their schools fail to measure up under the law, which sets stringent new standards for performance.
While salary and benefits are also stumbling blocks in the dispute, the 216 striking teachers and the school board in this city of 5,400 people about 40 miles from Portland are wrangling over contract language related to No Child Left Behind. Several marathon bargaining sessions have stretched into the wee hours.
"No Child Left Behind is creating issues we didn't expect four or five years ago," said Larry Wolf, who heads the Oregon Education Association, the state teachers union. "The law's approaching deadlines raise flags for both sides."
Under No Child Left Behind, schools must bring increasing percentages of children from all backgrounds up to scratch on reading, math and writing tests. Schools that repeatedly fail to make enough progress face a series of sanctions, the most serious of which include school closure and takeover by a private company.
The law also includes says that by the end of this school year, teachers must be "highly qualified" in the subject they teach. That definition varies from state to state but generally means that teachers must have majored in the subject they teach, must be certified by the state and must pass an exam in the topic.
Teachers in some places are pushing for contract language to protect themselves.
In Oregon, unions are asking for the right to take part in developing new curriculums required under No Child Left Behind, and want assurances that staff members will not be replaced or transferred if a school fails to make enough progress under the law.
Teachers also want to make sure that student performance on tests is not the basis for negative action against an employee. And they say school systems should not be able to take into account whether a teacher has been deemed "highly qualified" during layoffs or recalls.