In spelling out a vision for education reform in America, President Obama announced on Tuesday that he embraces merit pay for teachers (see related story). The head of Philadelphia's teachers' union says he backs Obama's proposal but wonders what the effects will be once the plan is fleshed out. Philadelphia Federation of Teachers president Jerry Jordan (right) says Obama's endorsement of merit pay for improved student perfomance doesn't go against what his union has been fighting for: "He talked about competitive salaries for teachers with innovative ways to reward teachers and experiences. We have been advocating those things at the...