Predictions are a mug's game in today's volatile politics, but I stand by the one I made on these pages back in September: if Labour goes into the next general election led by Jeremy Corbyn, the party will receive the lowest Jewish vote in its history.
If anything, that wager is looking even firmer now, thanks to the serial revelations of assorted antisemitic cranks admitted and readmitted into the party, even holding elected office. Nothing I've seen suggests that Jewish voters will be in a mood to overlook that when it comes to choosing a new government in 2020.
But an earlier test is coming. Next month, Londoners will elect a new mayor and it's easy to imagine Jews channeling that anti-Corbyn sentiment into a vote against Labour's candidate Sadiq Khan. After all, they'll be reluctant to hand the new leadership anything that looks like a vote of confidence. What's more, Khan was one of those MPs who nominated Corbyn last summer, thereby ensuring the Islington MP a place on the ballot. Surely all that should add up to a Jewish thumbs-down for Khan on May 5.
Not so fast. For one thing, there were quite a few Labour MPs - "morons," one Labourite called them - who nominated Corbyn not because they agreed with him but to "widen the debate." Most of them, Khan included, did not vote to make Corbyn leader. Cretinous the logic may have been, but it does not make Khan a Corbynite.
That much has been proven since. Witness the leaked assessment by Team Corbyn that Khan was among those Labour MPs deemed "hostile". Nowhere has that antagonism been more visible than on Labour's antisemitism problem. Khan has led the charge, regularly faulting Corbyn for failing to act more swiftly and decisively.
Some argue he is making admirable efforts to mend fences
At last week's JW3 hustings, Khan said he wore "a badge of shame" over the issue, that antisemitism in Labour made him "embarrassed and sorrowful." He suggested Labour's ruling national executive submit to training to better understand anti-Jewish racism and once again criticised the party leadership for not taking a "tougher stance."
Some will roll their eyes at these efforts to reassure the Jewish community. It's just a politician chasing votes at election time, they'll say. But this has come at a price for Khan. He's taken heat in some quarters for coming out against BDS - boycotts, divestment and sanctions against Israel - and for promising not to use his mayoral platform "to offer commentary on foreign policy" (a coded pledge to be no Ken Livingstone). If this were pure electoral calculation, Khan would surely have decided that there are more Muslim votes than Jewish ones in London and it was smarter to say nothing.
The less cynical view is that Khan is making an admirable effort to mend fences whose damage long predates Corbyn. Most impressively, he has drawn on his own life experience as a Muslim to empathise with London's Jews, stressing that he will support security at Jewish schools and synagogues as well as protecting, in his words, "religious freedom regarding shechita and brit milah." As one Jewish community bigwig put it to me: "He speaks our language."
This surely is the prize here, bigger than the satisfaction to be gained by poking Corbyn in the eye: the chance for the world's greatest city to be led by a Muslim mayor who has, for example, made a point of breaking his Ramadan fast in a series of synagogues. What a message that could send, to Britain and the wider world. I hope that Jewish Londoners, whatever doubts they harbour over the party leadership, give Sadiq Khan a chance. He's earned it.