Mitch Smith of The New York Times retrospectively wrote that in these positions, Vallas "cultivated a reputation as a crisis manager and charter school supporter willing to take on hard jobs and implement sweeping changes, an approach that garnered a mix of praise and criticism".

[8] In a 2009 article in the Education Next academic journal, Dale Mezzacappa wrote of Vallas's leadership style in his Chicago and Philadelphia superintendencies "His energy level is boundless, his temper legendary, his gangly charm equally so.

To address that deficit, Vallas submitted a plan that he claimed would save $162 million by reducing 1,700 central office staffers, raising cash by selling 20 surplus properties, and eliminating a program, described as "elaborate", to network the district's computers.

In later years, in tandem, a decrease in returns from the stock market and an increasing number of retirees would cause the CPS to be unable to make their full payments on time.

This has been identified as an inciting incident for the subsequent $1 billion budget crisis, attributed largely to spiking pension payments in later years.

[14] $666 million in capital bonds that the district took out under Vallas's leadership are anticipated, as of 2023, to ultimately cost the city $1.5 billion when interest is factored in.

Martha Woodall of The Philadelphia Inquirer wrote in 2002 that, in Chicago, Vallas attained a reputation of being, a "savvy, hard-working, blunt-speaking manager who insists on doing things his own way".

[18] In a 2009 article published in the Peabody Journal of Education, Elizabeth Useem wrote that, as CEO of CPS, Vallas, "developed a reputation for being an energetic leader who could move quickly to carry out a far-reaching program of reform".

[20] In July, Connecticut Superior Court Justice Barbara Bellis ordered Vallas removed from the position after he neglected to complete mandated coursework and certification.

[32][33] In January 2017, Governor of Illinois Bruce Rauner appointed Vallas to a vacant seat on the board of trustees of Chicago State University.

[7] After the 2014 gubernatorial election, Vallas worked with the Bronner Group and the United States Department of Justice to develop a prison education program.

[44] On Thursday, September 9, 2021, "The Arkansas Board of Education ... gave final approval to four open-enrollment charter schools to begin operations in 2022 and 2023.

"[51] In addition to Poshard's support, Vallas also received the endorsements of the editorial boards of the Chicago Tribune[52] and the St. Louis Post-Dispatch.

[55] During his tenure as superintendent in Louisiana, he floated the possibility of running for office back in Illinois, but ultimately did not pursue either race.

[64] When he entered the race, Vallas was seen as a potentially strong opponent to incumbent Rahm Emanuel, seeking reelection at the time.

[68] After Emanuel withdrew his planned candidacy, a large number of prominent political figures adjoined the field running for mayor of Chicago.

Among the contenders to enter the race at this point was Gery Chico, Vallas's one-time political ally with whom he had previously overseen the Chicago Public Schools.

[89] Vallas was a critic of the Lightfoot administration over what he characterized as her lack of accountability amidst a rise in crime and violence in the city.

[93] The month that he launched his campaign, Vallas appeared at a fundraising event for Awake IL, a political not-for-profit that had been criticized for its anti-LGBTQ rhetoric.

[96] Reporter Gregory Pratt later claimed that the Chicago Board of Elections had said that Vallas had not voted in the Republican primary and that the records that showed him as having done so were due to a "coding error".

Edward Robert McClelland of Chicago magazine remarked that his being the sole White candidate meant that, unlike in the 2019 mayoral election, "[Vallas] doesn't have to share that constituency with Bill Daley, Jerry Joyce, or Garry McCarthy."

[98] Similarly, Justin Kaufman of Axios opined that Vallas is "the candidate most likely to court the police and firefighter vote".

[102][103] Also endorsing Vallas were Chicago aldermen Brian K. Hopkins[104] Anthony Napolitano,[105] Brendan Reilly,[106] and Tom Tunney.

[110] Vallas also received significant campaign donations from sources considered politically conservative and aligned with the Republican Party.

[111][108][112] Vallas was criticized by opponents for holding perceived conservative political positions, in particular allegedly opposing abortion rights.

[8] Some analysts believe that Vallas benefited greatly from staking out a "tough-on-crime" stance amid widespread concerns among Chicagoans about crime.

[144][145] Two-time mayoral candidate and former chair of the Illinois State Board of Education Gery Chico, who had worked alongside Vallas when they were leaders of the Chicago Public Schools, also endorsed him.

[146] Chicago Fraternal Order of Police union president John Catanzara stated in an interview with The New York Times that there would be “blood in the streets" if Brandon Johnson was elected.

[149] Continuing the charge prominently led by Lightfoot and García in the first round of the election, Johnson characterized Vallas as a Republican masquerading as a Democrat.

The Vallas campaign released a statement confirming Gus's involvement in the shooting, saying that the complete investigation found him to have not been "engaged in any violations of policy or procedure" and that he had been returned to "full duty".