The NYPD and the FBI have been rivals since the days of J. Edgar Hoover. Until recently, the NYPD had performed domestic surveillance work for the CIA, another FBI rival, even in states like New Jersey and Pennsylvania, outside their jurisdiction. Keep in mind Rudy Giuliani, a close adviser to Trump, was a former New York policeman, as well as that city's mayor for a decade. As mayor, he was very much pro-police, untying their hands after decades of liberal administrations. Also, the NYPD is still dominated by Irish and Italian Americans. Of course, Trump is neither, nor for that matter a Catholic. He is a white Protestant, but from first and second generation parents, and certainly not a blue blood of colonial stock. Non-Jewish, non-Yankee whites in the Northeast are a distinct group, one that has lost much political power over the last few decades. Many officers of the NYPD thus would regard Trump as one of their own. Hillary Clinton is a Illinois/Ivy League/Arkansas carpetbagger who is known to be contemptuous of LEOs, as evidenced by her mistreatment of Arkansas state troopers and the Secret Service.
The NYPD had plenty of reasons to pursue Hillary Clinton through its probe into Huma Abedin's degenerate husband. They forced Comey's hand in all probability.
Maybe there really will be some justice, no thanks to the Obama justice department.
It appears that Comey’s intentional foot dragging on the initial investigation has come back to haunt him, the DOJ, Obama and the Clintons.
This newly disclosed trove of emails would not be a surprise find if if the FBI had aggressively and earnestly pursued all potential lines of evidence in the initial investigation instead trying to cover for Hillary.