It is not the fault of the teacher when a child refuses to learn. Learning must start and end at the home. Teachers have been increasing blamed for low test scores. Some states want to pass a law to base teacher salaries on student performance.
This would create an unfair disadvantage to certain teachers. Schools and classes are usually broken up into levels of student achievement. Students with higher test schools are separated from ones with lower test scores. Magnet schools will always test higher than non-magnet schools. Many schools follow this type of grouping.
Teachers are already faced with many obstacles including constant budget cuts, uncaring parents, and unruly students. We can't expect them to teach our children while also fearing potential loss of income.