Soros is ineligible but if he were allowed to run he would win against Adelson. Higher name recognition and better-looking. It would be close as Adelson has a higher net worth. But we've seen with Bloomberg that money is far from everything.
You underestimate the power of right-wing antisemitism. Sure, some antisemitism (along with a myriad legitimate criticisms) would be thrown at Adelson from the left, but the antisemitic Soros campaign has been one of the most mainstream antisemitic campaigns in history. This would be one of the most awful elections I could imagine for Jews, and Adelson would win.