During a rare in-person mayoral forum on Wednesday, frontrunner Andrew Yang was forced to explain to a roomful of public school educators remarks he made last month in which he blamed the teachers' union for holding back the full reopening of city schools during the ongoing COVID-19 pandemic.

Yang backed down slightly from his criticism of the union, crediting a conversation he later had with Michael Mulgrew, the head of the United Federation of Teachers, that he said convinced him Mayor Bill de Blasio was to blame for the struggles with school reopenings during the crisis.

"The mayor has failed people like me," said Yang, whose two sons attend public schools.

The moment was one of several during the 90-minute far-ranging discussion in which Yang was scrutinized by Mulgrew on his positions and knowledge of the public school system.

Seated next to Yang in the forum were his main Democratic rivals: Eric Adams, Scott Stringer, and Maya Wiley. Unlike other groups hosting mayoral forums, the UFT elected to pare the field down to four leading candidates who have performed better in polls. Although the decision left the one candidate who was a former public school teacher, Dianne Morales, out of the event, the smaller forum, held at UFT headquarters in the financial district, allowed for a more focused discussion. Mulgrew and other educators grilled the contenders on issues ranging from gifted and talented programs to the growing number of homeless students.

The event amounted to an interview process for the 190,000-member union, which has yet to announce who it is endorsing for mayor. Mulgrew himself said that the union wanted to "make sure we have a partner that is going to work with us."

Read more: Who Are The Labor Unions Backing 2021 Mayoral Candidates?

Yang, who also supports charter schools, is not expected to win the UFT endorsement in the primary. But with the overwhelming majority of city schools only partially open, his attacks on the teachers' union could help him win over parents who want to see a full reopening of all city schools.

Of the candidates, only Yang and Stringer currently have children in the public school system.

Stringer has proposed the most detailed plan on education—a slate of proposals that would cost more than $1 billion and would include adding teachers and expanding city-funded childcare and after-school programs.

The candidates were in agreement on many issues, such as addressing the surging number of homeless students—more than 100,000 as of last fall—by building more affordable housing.

Yang has proposed using hotels, while Stringer stressed his housing plan, which would also require any as-of-right development with 10 or more units to set aside 25% as affordable housing.

All four candidates have said they agree with the administration's long-awaited decision to scrap gifted and talented tests for four-year-olds, although they said they were not willing to do away entirely with the program.

On whether the city's eight specialized high schools should be able to base admission on a single test, Stringer and Wiley said no. Yang said he would instead add additional criteria. Adams said he would allow the practice, but argued that there was too much focus on a handful of schools and that he would open additional specialized high schools—a position that other candidates have also echoed.

Asked whether school PTAs should be required to share their funds with those in underfunded communities, all of the candidates said yes except Yang, who said the decision should be left to the schools.

In the wake of the pandemic, all of the candidates agreed that online learning would continue in some form, with Adams arguing most forcefully for its continuation during the summer to extend the school year.

Each of the candidates was allowed to ask one question of another candidate. In a preview of future forums, Adams, who is polling in second place, elected to use the opportunity to skewer Yang, accusing him of not saying hello to him in the hallway preceding the forum.

Yang denied the allegation, saying, "I had two masks on."

Adams renewed his criticism of Yang for leaving the city for his second home in New Paltz during the early days of the pandemic and for what many interpreted as his tone-deaf remark about the challenges of doing remote learning in a two-bedroom apartment.

"I put my life on the line and I know these teachers put their lives on the line," he said. "Why did you leave the city?"

Yang said that his quote about his living situation in the city had been taken out of context. He argued that he was spending time outside the city in order to campaign for President Joe Biden and later to help unseat two Republican Senate incumbents in Georgia.

"New Yorkers know that I’ve been doing things that I thought would be helpful," he said. "They also sense that I’m on their side."