Since entering Congress in 2013, the formerly mild-mannered Hakeem Jeffries has morphed from Clark Kent into Superman.

At least, the former state assemblyman from Brooklyn appears that way in his criticisms of the NYPD -- and most recently, of Mayor Bill de Blasio.

At a meeting of black leaders in Harlem in May, Jeffries lambasted the mayor for failing to end NYPD Commissioner Bill Bratton's "broken windows" policy, which de Blasio supporters say discriminates against black and Hispanic New Yorkers.

In The New York Times, Jeffries attacked the mayor for refusing to support a law banning chokeholds by police after the death of Eric Garner in Staten Island. He blamed de Blasio for "his willingness to support making resisting arrest a felony," and he said the mayor had taken undeserved credit for ending the overuse of stop-and-frisk.

"You didn't get rid of stop-and-frisk," Jeffries said at a May 9 rally in Harlem. "The movement got rid of stop-and-frisk. . . . What you've done -- based on the actions of Rev. [Al] Sharpton and activists and legislators and families and so many others who compelled, who pushed that federal court to declare stop-and-frisk unconstitutional, what you've done, you've implemented a federal court order. That's all that happened."

Jeffries' rhetoric has become strident enough that, as the New York Post reported Friday, some black ministers suggest he might challenge de Blasio in 2017.

A Jeffries spokesman did not respond to requests for comment.

It must be noted that some of Jeffries' comments have been disingenuous and even untrue. At a May 19 House Judiciary Committee hearing on police reform, he lit into controversial black Sheriff David Clarke of Milwaukee over Eric Garner's death, saying, inaccurately, that Garner never resisted arrest.

Clarke said "the elephant in the room" was black-on-black crime. Separately, Bratton has told this reporter that "the vast majority of the violence in this city is minorities committing violence against other minorities."

At the hearing, Jeffries said whites kill whites at the same high rate. But he ignored the fact that homicide is not the leading cause of death of young white men, as it is for young black men.