Days after he started, a series of emails surfaced implying a romantic relationship between the married Carvalho and former Miami Herald reporter Tania deLuzuriaga when she was covering the school board, which would have raised judgment and conflict-of-interest issues. Carvalho denied the allegation and district officials have said they could not authenticate the emails.

That controversy has faded, and the public perception of the Miami-Dade County Public Schools has shifted from dark to rosy.

“The superintendent has really turned things around,” said Sharon Watson, president of the Miami-Dade County Council of PTA/PTSAs. She waited at Miami International Airport to surprise Carvalho as he returned from the Broad Prize ceremony in New York City: “It’s like welcoming back the Super Bowl team.”

In many ways, Carvalho acts like a politician. He understands local politics, unlike his old boss, Crew. He speaks off the cuff about policy and rattles off statistics. He chooses his words carefully, tailored to the audience and with an inspirational arc. He greets voters at the polls. He even reminds board members to watch their words because “we are the candidate.”

“I think he’s done really well,” said School Board member Raquel Regalado, who has joined him on the campaign trail. She added it’s not a “pure election,” but there is that “vulnerability” of being rejected.

Education observer Brian Peterson recently wrote in an email newsletter how Carvalho has a knack for giving board members enough of what they want to keep unity: “So we credit Carvalho with being a smart, successful politician. If he can win the school bond referendum on top of the Broad Prize, he is golden,” Peterson wrote. “If Carvalho is golden, then we would like him to take over as county mayor and to merge the school system and the county.”

Carvalho capitalized on the prize for the bond campaign. Arriving at the Miami airport, he flexed his muscles as he entered Concourse D and told reporters the award was another reason voters should support the bond. The next day, he hit the local media circuit, including a stop at Versailles on Calle Ocho, and brought the trophy to an interview on Spanish-language America TeVe Channel 41.

Bond or no bond, the job of a superintendent is more political than it may seem, said Sean Foreman, a political science professor at Barry University. The chief must advocate with state and federal governments, deal with constituents and the board and understand policy.

“Mr. Carvalho is a political animal,” Foreman said, citing his communication skills and understanding of education dynamics.

The bond campaign has put those skills on display, especially his communication savvy.

Carvalho can make the pitch in English and in Spanish and tell Haitian-Creole speakers the bond is “pour les enfants.”

At a media tour of Hialeah Senior High and its cracks and water damage, Hialeah and Miami Springs politicians sweated in the humid, open-air hallway until Carvalho arrived late. (He squeezed in a “desperately needed” haircut.) He teased Mayor Carlos Hernandez, a 1979 graduate of Hialeah High, that they had questions about what was in his old locker. Explaining his support for the bond, Hernandez cited Carvalho and the board.

“They have done an incredible job. I know people worry about the past. I’m very confident in what’s been said today in how it’s going to be done,” Hernandez said. “I’m going to go out there and be a wingman for the superintendent.”

Carvalho also managed to ease potential opposition from the black community, concerned about equity in construction and contracts to black businesses. After a tense forum in September at New Birth Baptist Church in North Dade, Carvalho invoked President Barack Obama and told people that, like the president, he shouldn’t be blamed for inherited problems.

The district’s advisory group for minority- and women-owned businesses hashed out a new business policy, which Carvalho got approved by the board.

Privately, he met with a small group of black elected leaders at a Biscayne Boulevard restaurant. The next day, officials, including County Commissioner Audrey Edmonson, Miami Gardens Mayor Oliver Gilbert and state Sen. Oscar Braynan, attended a live radio broadcast and tour at Miami Norland Senior High.

The tense questions from New Birth faded. On a live broadcast, the church’s leader, the Rev. Victor Curry, endorsed the bond and praised not only Carvalho, but the school’s cookies. The staff quickly delivered a fresh batch, with milk.

Miami Herald staff writer Patricia Mazzei contributed to this report.