Mayor Bill de Blasio just took a huge step toward uniting the city . . . against his moronic claim that anti-Semitism is exclusively a “right-wing movement.”

The mayor dropped that one at a Tuesday press conference about the spike in hate crimes — up 64% over last year, with anti-Semitic incidents, already the largest category, jumping 90%.

Plenty of anti-Semitism is unmistakably right-wing, of course. But it doesn’t matter that de Blasio qualified his charge: “The violent threat, the threat that is ideological, is very much from the right.”

Tell that to ISIS, or the Islamists that rule Iran.

Or Jeremy Corbyn, the leader of Britain’s Labour Party.

Here in America, tell it to Louis Farrakhan, and his fans such as activist Linda Sarsour — one of the leaders of the Women’s March.

Not to mention Rep. Ilhan Omar, who can’t seem to stop uttering classic anti-Semitic tropes. Maybe the mayor thinks her bias is just cultural, rather than ideological?

Perhaps de Blasio was trying to say that the wave of attacks on Orthodox Jews in Williamsburg and Crown Heights is not ideological. As NYPD Chief Dermot Shea reported at the same press conference, hate crime perps “run the gamut” from teens, to people with mental illness, to first-time offenders and career criminals.

But the sad fact is that Jew hatred (like racism and most other forms of hate) pops up all across the spectrum, and almost any ideology can be twisted into “justifying” it.

Which most people understand. Thus Councilman Chaim Deutsch, a Brooklyn Democrat whose constituents are leading victims of hate these days, noted: “I don’t agree with the mayor . . . I have not seen any white supremacists coming in here committing these hate crimes.”

But the last word rightly goes to Councilman Joe Borelli (R-SI): “Bill de Blasio regularly says stupid things, but this is literally the stupidest effing thing he’s ever said.”