Will a jury with black members convict a black mayor in New York? That is highly doubtful.
Due to five black jurors, in 1990, DC Mayor Marion Barry famously beat the rap in a drug case spite of compelling proof on video. Similarly, in Tallahassee, in a case that AG Pam Bondi would have seen in the media, the loyalty of a black jury meant that the federal government could not get a conviction of a black former mayor for corruption.
There is simply no good reason for the Trump Department of Justice to want to be accused of racism while almost certainly losing a criminal case against the black mayor of New York for illegal gifts that resulted in minimal if any harm to the public.
B!@#$ set me up.