PHILADELPHIA

They all voted for it, but that was then. 

Democratic presidential candidates came out swinging Monday, not at each other but at the No Child Left Behind law.

They spoke at the annual convention of the National Education Association, the nation's largest teachers union.

While the candidates received a warm response in the City of Brotherly Love, mere mention of President Bush's signature education law elicited loud hisses and boos from the thousands of teachers on hand.

The law, passed with broad Democratic support in 2001, requires public school students to be tested annually in reading and math in third- through eighth-grade and once in high school. It is up for renewal this year in Congress.

An NEA criticism of the law is that it forces teachers to spend too much time on test preparation instead of other forms of instruction, and many teachers wore buttons or stickers reading, "A child is more than a test score."

Sen. Chris Dodd, D-Conn., sported the sticker on his own lapel as he called for the law to be overhauled. "It's time that we get this law right," Dodd said, saying it needed higher funding levels, among other things.

Dodd and John Edwards, a former vice presidential candidate and North Carolina senator, both stressed that they have school-age children and therefore have personal as well as political insight into what's happening in the nation's schools.

"These tests do not tell us what we need to know about our children," Edwards said.

Sen. Hillary Rodham Clinton, D-N.Y., said she has heard stories about teachers shaping their lesson plans to ensure their students do well on the reading and math tests at the expense of other subjects.

"The test is becoming the curriculum when it should be the other way around," Clinton said.

Clinton's call for universal preschool for 4-year-olds and smaller class sizes won cheers, as did Edwards' comments about improving low-income students' access to college.