The mob attacks on Jewish Americans in the streets of New York City and Los Angeles aren’t just an echo of the war between Israel and Hamas. They’re the fruit of delegitimisation and incitement in America’s schools, mosques and media — and of the corruption of the Democratic Party, whose rising stars and fading leaders have all fanned the flames for electoral gain.

The Democrats are becoming Corbynised. The radical left sets the pace and tone, the soft left simpers along and the party leadership rides the tiger into office.

We saw it when senior Democrats endorsed the Million Man March while pretending not to notice the open antisemitism of its Farrakhan-loving co-founder Tamika Mallory.

We saw it when Nancy Pelosi, the Speaker of the House, responded to the antisemitic words of Ilhan Omar and Rashida Tlaib by posing alongside them and other members of ‘the Squad’ on the cover of the Rolling Stone magazine.

We saw it during the Democratic primaries, when Bernie Sanders sat down with Al Sharpton, a man who incited the pogrom in Crown Heights in 1991.

We saw it last year when Joe Biden took a knee for Black Lives Matter, whose one-point foreign policy is that Israel is an illegitimate “apartheid” state.

We saw it again when BLM supporters ransacked Jewish shops, vandalised synagogues and called for an American intifada. The Democrats embraced the Arab Spring pose of “resistance”, Democratic mayors looked the other way and the police backed off. Biden and Pelosi praised the kids for their good intentions, even if they had got a bit rowdy, and Kamala Harris even called for more.

It’s not like the Democrats have a blind spot about this. They see the electoral advantages. Race remains the American dilemma. The Republican right dog-whistles to the racists in the backwoods, while the Democratic left says it loud and proud in the cities.

The Jews aren’t just collateral damage in the making of the rainbow socialist coalition. We’re in the crosshairs of intersectionality: “white-adjacent” by race, as the woke say, and capitalist class exploiters as usual. Add an American-sized double scoop of ignorance and sanctimony, put a cherry of race-guilt on top and the “white” Israelis are repeating America’s original sin by dispossessing the “brown” Palestinians.

“What they are doing to the Palestinian people is what they continue to do to our black brothers and sisters here,” Rashida Tlaib told a rally just after the Israel-Hamas fighting began this month.

She then called Israel an “apartheid state” in Congress. House Democrats overwhelmingly voted against applying sanctions on Hamas, which by then had launched thousands of rockets at Israeli civilians. Bernie Sanders and the Squad attempted to block the sale of precision munitions to Israel.

An Economist/YouGov poll found that 61 per cent of Republicans supported Israel, but only 16 per cent of Democrats did. Thousands marched in Tlaib’s home state of Michigan, calling for “intifada”. When Biden flew to Michigan, Tlaib met him on the tarmac. Afterwards, he praised her as “a fighter”.

When a lone gunman massacred Jews at the Tree of Life synagogue in Pittsburgh, I wrote that Donald Trump and his Republican allies bore a partial responsibility. Not for the killer’s actions but for degrading the tone of public life, and exploiting the long, digitally-enhanced continuum that leads from the violent fringe all the way to the voting booth.

The same applies now to Joe Biden and the other Democratic leaders. They have ridden the tiger and returned Jew-baiting to the streets of America. Of course, once roving gangs of social-justice activists were beating up Jews in the streets of Democratic-run cities, they tried their best to dismount.

During the Gaza fighting, Alexandria Ocasio-Cortes whipped up the mob by calling Israel an “apartheid” state and adopting the language of Hamas by falsely accusing Israel of “attacks on al-Aqsa”. Then people started acting on this kind of talk.

In Los Angeles, members of a pro-Palestinian caravan got out of their cars to hunt down Jews and beat them up in the street. Two drivers tried to run over a Jew who escaped.

In New York, a kippah-wearing Jew was kicked on the ground in Midtown Manhattan; the New York Times attributed it to “clashes” between supporters of Israel and Hamas.

A mob rampaged through the Diamond District, and one of its members threw an explosive device. In Brooklyn, two Orthodox teenagers were menaced with baseball bats and forced to shout “Free Palestine”, then beaten up anyway.

“We will never, ever tolerate antisemitism here in NY,” AOC tweeted. But she hasn’t just tolerated it. She’s encouraged it.

So have her allies on the left. And so has Joe Biden. When the President of the United States praises someone who lies about Israel and incites violence against American Jews, he sends a message.

What happens next depends on whether the largest, most prosperous and powerful community in the history of the Diaspora is listening.

Dominic Green is deputy editor of The Spectator’s World edition