A few years ago, WhatsApp co-founder Jan Koum struck up what might have seemed, from the outside, like an unlikely friendship with Miriam Adelson. Koum, then in his mid-40s, was a reclusive multibillionaire who had retired to tend to his hobbies, including “collecting rare air-cooled Porsches” and “playing ultimate frisbee.” Adelson, in her 70s, was for decades better known as the wife of Sheldon Adelson, the casino magnate and Republican megadonor. But the two crossed paths at a fateful moment in both their lives. Koum, an observant Jew who had begun pouring money into Zionist causes, was becoming increasingly interested in politics. And Adelson, who was still mourning the January 2021 death of her husband, perhaps saw in Koum someone who might take up his mantle.