A proposed realignment of pay in Washington, D.C., public schools could be the most sweeping of all. Teachers with as few as six years of experience could earn well over $100,000 — more than twice the national average.

The pending contract is still in negotiation with the teachers' union. The sticking point is that D.C. Schools Chancellor Michelle Rhee wants teachers to give up traditional tenure and seniority protections. She also would require all teachers who want the big raises to work under probationary status for a year. Under the "green tier," even decorated teachers could be out of a job if they don't produce.

"I get e-mails every day from teachers who are like, 'I'm going green in a second,' " Rhee says. " 'I know I'm a great teacher. I have no problem going through the probationary period. I'm good.' I've had some people say, 'Take tenure away period. I don't care. I can produce the results.' "

George Parker, president of the Washington Teachers Union, says, "A lot of our younger teachers say, 'Bring it on.' " Older teachers, he says, want a sense of due process.

Education reformers of all political stripes have long called for a new way to pay teachers. Both presidential candidates support differentiated pay, making it likely the issue will affect teachers nationwide.

"We just need much more experimentation and dynamism on this," Duke University economist Jacob Vigdor says. "We're not going to fix this by coming up with one new system that replaces the old system. We need to be trying a lot of things."

Teachers are divided. A survey in January found 88 percent support bonuses for those who agree to work in hard-to-staff schools; 35 percent support them for improved test scores. Many say they don't trust test scores to accurately reflect their efforts.