Mayor Bill de Blasio and Gov. Andrew Cuomo have pledged to support immigrants here illegally who might face deportation by the Trump administration.

The mayor promised to maintain NYC’s sanctuary city status, meaning that city officials and local police will not assist federal officials in immigration enforcement.

The governor said that any effort to deport immigrants should start with him, the grandson of immigrants. He also proposed setting up a legal defense fund to help low-income immigrants fight deportation proceedings in the courts.

Students and faculty at the City University of New York, however, are deeply concerned, especially about those students who have some kind of criminal record. Donald Trump has repeatedly emphasized his desire to deport the “criminals” within the immigrant population.

While most of these young people do not have criminal records, some do. This is in large part a result of the city’s ongoing emphasis on broken-windows policing. During much of the last decade, more than 200,000 people a year were arrested for low-level misdemeanors like being in the park after dark, possessing marijuana or urinating in public. The vast majority of those arrested are young people of color who could now face deportation proceedings.

The mayor and governor need to take steps to reduce this risk. First, the mayor needs to rethink his reliance on broken-windows policing to manage the city’s disorder problems. Rather than hiring more police to give out citations for turnstile jumping and being in the park after dark, the city should build public bathrooms, develop reduced-fare MetroCards for those in need, and schedule supervised nighttime hours in the parks.

The governor should erase the records of those who have paid fines or completed any court-ordered penalties, or he should grant pardons. He should also order CUNY to resist records requests from immigration authorities.

The mayor and governor have taken the first step by rhetorically pushing back against the threats made by candidate Trump. It is now time for them to act to block the actions of President-elect Trump.

Alex S. Vitale and Alan Aja are associate professors at Brooklyn College.