While the 65th anniversary of Brown v. Board of Education in May was ignored in most of the country—even though racial segregation in schools has significantly increased over the last 20 years—in New York City the issue has been the subject of controversy and intense debate. That’s been bad news for New York Mayor Bill de Blasio. De Blasio, who recently announced that he’s running for president, now finds himself compelled to address racial segregation. Like former NY mayor Mike Bloomberg, de Blasio has asserted on numerous occasions that he wants to control public schools in New York City. However, on the issue of segregation in schools, he seems more interested in hoping it will go away than in providing moral leadership.

Earlier this month a bill proposed by de Blasio and his allies calling for revisions to the admissions policies used at New York City’s elite high schools died from lack of support in the New York State legislature. We should not be surprised. Despite the fact that the lack of black and Latino students at the city’s seven elite exam high schools received considerable attention even before de Blasio was elected, the mayor invested little political capital and even less savvy in getting the bill through the Democrat-controlled legislature.

Instead of basing admissions decisions on how well applicants performed on a single standardized test (the SHSAT), under the mayor’s proposal middle school grades and geographic distribution would have been considered, thereby ensuring that a more diverse pool of qualified students.

Historically, New York City’s exam schools had been relatively diverse, relying on an unofficial racial quota system to ensure that top students from diverse backgrounds had access to the schools. However, since the 1980s, admission has been determined strictly by how well students perform on the SHSAT. Students who seek admission to these selective schools typically study intensely for over two years to obtain a score that will lead to admission. In recent years, the majority of those admitted have been Asian, and activists from Asian communities have been the most vocal opponents of de Blasio’s attempts to change the law.

Despite the fact that no college in the nation relies upon a single exam to determine admission, de Blasio’s efforts in support of his own plan were weak. While New York City Schools Chancellor Richard Carranza attempted to lobby the legislature, de Blasio invested little time or clout in the effort. Even when it became clear that his opponents were well organized—and some had received financial support from billionaire cosmetic heir Ronald Lauder—de Blasio downplayed the significance of the issue.

If de Blasio had been more interested in enacting a solution than he was in his dubious campaign for president, he might have realized that he had other options. He could have followed Bloomberg’s lead and put more money into efforts to prepare black and Latino students for the SHSAT. While it is unlikely that such an effort would have significantly changed enrollment patterns, it might have bought him time to create more high-quality schools in the city’s most impoverished neighborhoods. A 2012 study by the Annenberg Institute (“Is Demography Still Destiny?”) found 22 census tracts in New York City where less than 10 percent of high school students are considered college ready. In a city with more a million students, there is a glaring need for more high-quality school options.

The mayor could also have used the rapid gentrification of several neighborhoods to promote gradual, voluntary integration, since forced busing for affluent whites is out of the question. Instead, de Blasio’s timid response has allowed the issue to dog him throughout his tenure as mayor, and even onto the campaign trail in Iowa. Student activists from NY have repeatedly raised questions about the issue of school segregation at his campaign stops, and the mayor has tried his best to dodge the issue.

As we watch how the 2019 battle over school integration unfolds in one of the most liberal cities in the nation, it is easy to forget the great hope and promise that accompanied de Blasio’s election in 2014. Emerging from a field of candidates with a bold commitment to address inequality, de Blasio more than any other politician seemed in touch with the times. He recognized the importance of capitalizing on the energy generated by the Occupy movement, and after his election he quickly implemented universal preschool—the most ambitious educational reform carried out by any city in the country. However, as it became clear that the issue of racial segregation in schools would not fade (unlike the Occupy movement, which did), de Blasio never figured out how to respond.

In a city where 85 percent of students are poor (and either black or Latino), this failure has been a major stumbling block for de Blasio, both for his leadership as mayor and for his aspirations to higher office. Perhaps someone should remind de Blasio that “all politics is local,” and that if he wants to use his leadership of the nation’s largest city as a launching pad for his presidential campaign, he must demonstrate that he can actually lead.