Vallas' trouble with his bosses in Philadelphia began more than a year ago. Some observers at the time cited a power struggle pitting Commissioner James Gallagher and then-Commissioner Daniel Whelan against Vallas, who chafed at being treated as an employee and preferred acting as an independent leader. They clashed over the effectiveness of certain programs, the toughness of educational standards, and budget decisions.

Nevels and Commissioners Martin Bednarek and Sandra Dungee Glenn stood by Vallas, voting in August to give him a two-year contract extension. But Nevels' relations with Vallas became increasingly strained as the deficit unfolded.

The tall, gangly Vallas, dubbed a "whirling dervish" by the secretaries who kept his fast-paced schedule, said he wasn't surprised that "differences over governance" had marred his relationship with the commission and mayor. It's the typical course for a superintendent in a troubled urban district, said Vallas, who also ran the Chicago public schools for six years.

"The first two years you literally get to do just about anything you want. You're a demolition expert," said Vallas, who can spin the heads of his audience with his incessant speech and ability to rattle off details of his agenda.

"By year four, there's a lot of people walking around pissed off because you're getting so much credit for it. And by year five, you're chopped liver.

"It begins to come apart piece by piece, and it begins with micromanagement. You begin to lose the flexibility."

He won't stay in New Orleans as long: "Three years tops."

Critics and fans alike credit Vallas for raising the achievement of many of the district's lowest-performing students. More than 160 schools have met federal targets for improvement, compared with 26 when he arrived. Thirty-eight percent of students tested advanced or proficient in reading, up from 29 percent in 2002. The math proficiency rate jumped from 19.5 percent to 41 percent.

Vallas sought and got a technically advanced high school - now an international model - built in partnership with Microsoft Corp. It was one of about two dozen new, smaller theme-based high schools opened to give students choice.

High schools with Advanced Placement courses were increased from 18 to 48 in an attempt to boost rigor. Enrollment in early-childhood programs has nearly doubled. And nearly $80 million was spent on new textbooks.

Vallas built political goodwill for a district that had been non grata in Harrisburg, observers said.

But not everything went smoothly.

One of Vallas' first tasks was to establish a tougher "zero tolerance" discipline policy that would sanction principals who failed to report incidents and move out dangerous students to alternative schools. He rolled out the plan in September 2002, and in the next several years expanded disciplinary-school capacity threefold.

Yet assaults on teachers persist. The district was rocked in February after Germantown High School teacher Frank Burd was left with a broken neck from an attack by a student in a hallway. Chaos followed at West Philadelphia High after teachers complained of assaults. Violent incidents overall dropped 14 percent in 2005-2006, but are up slightly this year.

In another major initiative announced in his first year, Vallas said he would build nine high schools and almost as many elementary schools as part of a $1.5 billion capital program, the largest in the district's history. But progress stalled as the district struggled to find land and construction costs rose.

Eight high schools have been built or are being designed.

While the district built fewer elementary schools than projected, most of the capital program's renovation projects are done or in progress, officials said.

Vallas lowered class sizes early on, earning praise from the teachers union, but that effort faltered as funding tightened.

"Small class size has to be number one, and he didn't deliver," said Ted Kirsch, president of the Philadelphia Federation of Teachers, who generally praises Vallas.