CHICAGO — Paul Vallas took management of Chicago Public Faculties when the district was among the many nation’s most troubled. He went to Philadelphia to go up a teetering training system that the state had taken over. And after Hurricane Katrina washed away a lot of the New Orleans faculty district, he helped rebuild it.

Mr. Vallas constructed a repute as the tutorial emergency responder of the Nineties and 2000s, somebody sought out for probably the most difficult jobs. When he received to a brand new metropolis, he moved rapidly and forcefully, clashing at occasions with faculty boards and labor teams that objected to the tempo and scope of his modifications.

“I’ll do 10 issues and possibly accomplish 5 of them versus somebody who will do two issues and possibly accomplish one,” Mr. Vallas stated in an interview.

One in every of two Democrats in Chicago’s mayoral runoff election on Tuesday, Mr. Vallas highlights his file of enhancing amenities, holding colleges open extra hours and overhauling low-performing colleges. He additionally compelled out longtime educators, took a tough stance on scholar self-discipline and tremendously expanded the variety of constitution colleges, insurance policies that earned him followers and enemies wherever he went.

Mr. Vallas, 69, has put his training file on the heart of his marketing campaign for mayor of Chicago, arguing that town wants that model of disaster administration to decrease crime and enhance colleges. But he faces a modified political period during which lecturers’ unions have asserted their energy and plenty of Democrats have grown skeptical of the thought of college alternative, which Mr. Vallas helps and was as soon as broadly embraced by his social gathering.

Mr. Vallas is competing towards Brandon Johnson, a county commissioner and former instructor who embodies the progressive critique of Mr. Vallas’s training philosophy. Mr. Johnson, a paid organizer for the final 12 years with the Chicago Lecturers Union, has referred to as for sweeping new investments in neighborhood colleges and social applications. He desires to increase vocational applications, add assets for college students who don’t communicate English and keep away from closing colleges with low enrollments. He has additionally been on the entrance traces of three work stoppages as his union clashed with two mayors and articulated a liberal imaginative and prescient for Chicago that prolonged properly past colleges.

In Mr. Johnson’s telling, Mr. Vallas is an out-of-touch administrator whose insurance policies wouldn’t assist Chicago’s poorest residents. And when Mr. Vallas first ran Chicago’s colleges, Mr. Johnson stated, he made town’s entrenched issues even worse.

“The story of two cities has been dropped at us by Paul Vallas,” Mr. Johnson stated. “He created a stratified system.”

Mr. Vallas’s embrace of college alternative, together with magnet colleges, military-style academies and charters, was a central a part of the disaster playbook that he started growing when he ran Chicago’s colleges within the late Nineties. Again then, although, many liberals in addition to conservatives noticed constitution colleges as a manner to enhance struggling faculty districts like Chicago. Constitution colleges, that are privately run and publicly funded, are well-liked in lots of low-income neighborhoods as options to common public colleges. Lecturers’ unions, although, have typically bitterly fought the growth of constitution colleges, most of which aren’t unionized. The unions contend the colleges deprive the general public faculty system of assets.

Mr. Vallas got here to Chicago’s colleges from a finance function in Mayor Richard M. Daley’s Metropolis Corridor as an alternative of via the ranks of lecturers and principals. He took over Chicago Public Faculties in 1995 as Mr. Daley’s handpicked chief at a time of economic and academic disaster. The Illinois authorities, then managed by Republicans, had simply handed the mayor management of the system.

Mr. Vallas rapidly embraced different options to conventional neighborhood colleges, together with magnet colleges and military-style academies.

His insurance policies received reward from liberals who credited him with restoring order and elevating check scores utilizing a back-to-basics strategy.

The Clinton-era New Democrats had been ascendant, and Mr. Vallas in some ways epitomized the second, approaching the job like a company government; his Chicago Public Faculties title, in spite of everything, was chief government.

Underneath his management, the district positioned faltering colleges on tutorial probation, fired underperforming principals and ended social promotion, the follow during which failing college students had been superior from grade to grade merely to maintain them with their friends. The transfer helped him initially win over lecturers. An official on the American Federation of Lecturers hailed Mr. Vallas in 1997 for giving educators extra leverage over college students who weren’t doing their work.

“Individuals thought he was higher than sugar,” stated Josephine Perry, an teacher for a union that represents service staff in Chicago.

Years later, although, a lot of what Mr. Vallas has spent his profession championing — the powerful disciplinary insurance policies, the openness to constitution colleges — has misplaced a few of its bipartisan sheen. Ms. Perry, who stated she plans to vote for Mr. Johnson, summed up a priority of many Democrats: Mr. Vallas, she stated, is “extra aligned with Republican values.”

Although Mr. Vallas is a Democrat, he has campaigned on a tough-on-crime platform and is much extra conservative than Mr. Johnson. Mr. Vallas has additionally acquired endorsements from conservative organizations, together with the native chapter of the Fraternal Order of Police, and monetary help from some outstanding Republican donors.

The political divide on constitution colleges is sophisticated. A nationwide ballot final yr by Training Subsequent, an instructional journal, discovered {that a} majority of Black individuals surveyed supported constitution colleges, whereas fewer than half of white individuals and Hispanic individuals did. Alongside social gathering traces, Republicans supported charters at a far larger price than Democrats.

Mr. Vallas says it’s not a problem of Republicans versus Democrats. It’s about lecturers’ unions, which he stated have turn out to be “extra radicalized” with energy to form Democratic Get together politics.

“The unions realized that they had been dropping floor, and I feel it compelled them to turn out to be far more political than that they had been,” Mr. Vallas stated.

Leaders of the Chicago Lecturers Union, which has donated closely to the Johnson marketing campaign, stated that they had been defending public training in a metropolis the place mayors have repeatedly failed to speculate correctly in colleges. Stacy Davis Gates, the union president, stated she believed Mr. Vallas was going to shut some colleges and privatize others if elected mayor.

He “goes to marginalize Chicago Public Faculties in a manner that may make getting a public training nearly unattainable,” she stated.

Mr. Vallas says he desires to increase high-performing charters in Chicago however has not referred to as for eliminating neighborhood colleges.

Although evaluating tutorial achievement information over time is tough, Mr. Vallas compiled a combined file as a college government in 4 cities that included notable successes in addition to disappointments.

In Philadelphia, Mr. Vallas’s first cease after Chicago, proficiency in math and studying improved within the years after he arrived, in keeping with a examine by the RAND Company. However that examine additionally discovered that privately managed colleges in Philadelphia, which included some for-profit constitution operators, carried out no higher than district-run colleges, on common.

Ed Rendell, a Democrat who was governor of Pennsylvania for a lot of that point, stated he believed that Mr. Vallas did a great job below making an attempt circumstances, though not all of his concepts labored.

“He was an innovator,” Mr. Rendell stated. “Some his improvements had been good and had a constructive affect. Some had been well-meaning and well-targeted however didn’t work.”

Mr. Vallas’s tenure in Philadelphia ended after the district recorded a price range shortfall, which Mr. Rendell stated “wasn’t a catastrophe” but in addition “wasn’t acceptable.”

Mr. Vallas was particularly aggressive in spending on faculty building, which was additionally a theme of his tenure in different cities with decaying faculty buildings.

“He all the time informed me that if you happen to ship a child to high school in a college that has no paint on the partitions and a heating system that doesn’t work and it hasn’t been cleaned,” Mr. Rendell stated, “the child’s going to determine fairly quick that nobody values their training.”

However the scale of the change he sought, and the concept the system wanted an overhaul, made him loads of enemies. Kendra Brooks, now a member of the Philadelphia Metropolis Council, stated she received began in politics after watching with dismay as Mr. Vallas made intensive modifications to neighborhood colleges whereas increasing constitution and magnet applications. She described his tenure there as a failure that continues to harm town.

“If you restructure over 200,000 youngsters into a brand new system, it’s not straightforward to only flip again to one thing else,” Ms. Brooks stated.

Constructing a brand new system was precisely what Mr. Vallas was employed to do at his subsequent cease in New Orleans. He arrived in 2007, practically two years after Hurricane Katrina had washed away a lot of the varsity system, and needed to begin rebuilding earlier than it was even clear what number of college students can be returning to town.

To make it work, Mr. Vallas helped construct a community of constitution colleges overseen by public officers however largely unbiased of the type of forms sometimes related to big-city faculty districts. A Tulane College examine later discovered sustained enchancment in achievement and commencement charges within the new, charter-centric faculty system that he developed.

“Paul Vallas got here in to stabilize colleges. He didn’t are available to do constitution colleges,” stated Paul Pastorek, the previous state training superintendent of training for Louisiana and Mr. Vallas’s boss in New Orleans. “However I feel he acknowledged the worth of charters when he got here right here.”

Nonetheless, Mr. Pastorek burdened that Mr. Vallas was greater than prepared to shut constitution colleges that had been faltering, citing a 2011 resolution to shutter the Harriet R. Tubman Faculty within the metropolis’s Algiers neighborhood.

“Heavy political stress was utilized to maintain it open,” Mr. Pastorek recalled. “Paul advisable the state board shut it, and we did. Each faculty needed to meet the identical customary, together with charters.”

From New Orleans, Mr. Vallas went to take over the colleges in Bridgeport, Conn., in 2012. Invoice Finch, who was mayor of Bridgeport on the time, stated he was impressed with the velocity with which Mr. Vallas addressed price range issues, created tutorial applications and injected vitality right into a long-struggling faculty system.

“We went from a disastrous state of affairs to a traditional state of affairs,” Mr. Finch stated. “And I feel it was really higher than regular as a result of Paul actually innovated.”

However as in different cities, Mr. Vallas upset individuals with the tempo and sort of change he was proposing. He was finally compelled to go away after courts dominated that he didn’t have the right credentials to guide a Connecticut faculty district.

Now again in Chicago and working for mayor, Mr. Vallas continues to again constitution colleges and defend his training file towards criticism that he breaks greater than he fixes. He talks typically about utilizing colleges “to fill gaps,” getting eyeglasses to youngsters struggling to see and holding buildings open into the evenings to maintain college students secure and engaged.

“I’ve all the time been capable of multitask,” Mr. Vallas stated. He added: “I felt I needed to degree the taking part in subject.”

Julie Bosman and Dana Goldstein contributed reporting.