He has been calling retired police officers to ask what they think about his public safety plans.

He had a video meeting with active officers to find out how he can win over the rank and file.

Over biryani, chicken tikka and roti at a Pakistani restaurant in Queens, he listened as two dozen officers peppered him with questions about his past calls to defund the police.

Slowly and carefully, Zohran Mamdani has been seeking to make inroads with the New York City police, a constituency that views him with deep skepticism and even hostility.

Many officers have not forgotten comments he made five years ago, when, amid protests over the police killing of George Floyd in Minneapolis, he called for defunding the Police Department. Or his comments on social media that same year calling the police “racist, anti-queer & a major threat to public safety.” And many officers are wary of his plans to create a Department of Community Safety that would dispatch mental health workers, rather than the police, to respond to 911 calls for people in crisis.

Mr. Mamdani, a state assemblyman and democratic socialist who is leading in the polls after winning the Democratic primary, has called his past remarks “out of step” with his current views.

Nonetheless, police union leaders are prophesying a mass exodus of officers should he win in November. Louis Turco, the head of the lieutenants’ union, said he would need to hear an apology from Mr. Mamdani before he even considered meeting with him.