"Why are you two boys running?" Michael Johnson asks two sheepish-looking eight year olds. "You know it's dangerous, next time I'll have to call your parents."
By Catherine Miller
BBC, in Chicago, Illinois
The scene appears ordinary but this small display of discipline is something of a revolution for Reavis Elementary on the South Side of Chicago.
Starting with small actions like this Mr Johnson, who took over as principal at the start of the school year, is trying to dig the school out of a long history of failure.
"When you have a school that hasn't had a lot of academic success for a long time, coming into that culture is very difficult," he said. "The challenge to the status quo can be very threatening, even though it may be something for the best".
The status quo for Reavis is grim. Of its 600 mainly African American pupils, 92% live below the poverty line and last year fewer than a quarter met state-wide testing standards in English and maths.
Under the federal No Child Left Behind programme, introduced by President George W Bush in 2002, that has consequences not only for the children's future but for the future of the school.
Cycle of failure
The scheme aims to have all America's children up to a certain standard by 2014.
Schools, like Reavis, which do not meet yearly progress targets have to use their federal funding to offer students alternatives, for example, by offering transfers to better schools or by buying in tutoring services.
If they fail to improve over six consecutive years, they can be forced to close.
George Bush signing his act into law [ US Department of Education ]
The aim is to focus the minds of failing institutions and disrupt a cycle in which failure has become acceptable.
"Too many children in America are segregated by low expectations, illiteracy, and self-doubt. In a constantly changing world that is demanding increasingly complex skills from its workforce, children are literally being left behind. It doesn't have to be this way," Mr Bush said, laying out his proposals in 2001.
Reavis is exactly the kind of school that should benefit from such aspirations, but Mr Johnson says the law has not had the effect the president hoped.
"On paper, there are a lot of things will sound good about No Child Left Behind. In practice it ends up being punitive," he said.
"Schools do not operate in a vacuum, they operate in places where children are living in poverty.
"I don't want to make excuses but we also have to be real - people do need the resources that will help children learn."
That frustration has been picked up on the campaign trail.
Democratic presidential candidate John Kerry, who as a senator voted in favour of the No Child Left Behind law, accuses President Bush of creating an unfunded mandate. He promises to set up a trust fund to pour cash into the programme.
But dollars alone may not be the solution.
In the leafy northern Chicago suburb of Evanston, money is certainly not a problem.
The local property taxes, which produce the bulk of public schools' revenue, are high, and Evanston High School is well equipped with tennis courts, libraries and computer labs.
John Kerry advocates greater funding for the initiative
"This school is fantastic. We have phenomenal teachers and students our resources are incredible... it's by far one of the best schools, probably in the United States," said biology teacher Teresa Granito.
The Wall Street Journal agreed with that assessment when last year it put Evanston on a list of 64 "highly successful" American schools.
But according to No Child Left Behind, Evanston is failing.
"The federal government sets something called adequate yearly progress so you have to have 95% participation, you have to meet that standard for each racial group, as well as low income, special needs, bilingual students et cetera.
"We fell short for two consecutive years with our black and low income students primarily in reading and math," said school superintendent Alan Alson.
For fans of No Child Left Behind this is one of the law's great achievements. By demanding compliance from each subgroup of students, even good schools are forced to confront failures and are held to account for all their children.
Dr Alson, who has long worked to try to close the achievement gap between minority and majority students, supports the concept.
But the school has struggled to implement the sanctions which No Child Left Behind imposes on failing schools.
"You have to offer your students choice to go to another district that has met the standard of adequate yearly progress.
"We have three districts that surround us. Two of the three did not make adequate yearly progress and the third has chosen not to accept our students and therefore we are not able to offer choice to our students," Dr Alson said.
Experiences like this have raised questions about the practicality of implementing No Child Left Behind.
But Dr Alson worries that the scheme also has inherent educational flaws, which Mr Kerry's promised extra dollars will not change.
"What money won't do is address any of the key educational points around student progress and the kind of learning we desire for our students," he said.
"We have a democracy but it's a fragile democracy. An irony of the law is that it forces us to do things that are so narrowly focused they don't in fact help young people become the kind of citizens they need to be."
As election day approaches and the candidates wrangle over the nation's education, that is a warning America's 93,000 public schools will surely hope they heed.