They set themselves apart from the society. There is no universal law that various people will target Jews for no reason.
Nonsense. Medieval society was based on a senseless denigration of trade, since aristotle disliked trade and insisted that even if both parties agreed to it and felt they were better off for the trade, one was being ripped off. Since someone needed to do it, medieval society set up a caste to trade & lend money, which would be afforded opportunities denied others, but persecuted for enjoying them. Hypocrisy has its price, which is why it must be fought everywhere.
Today few hate commerce, and thus the root ideological problems that led to it have gone, as, I trust, eventually will go the racial bias resting on the same. natural law would have no less. In this sense Marxism was not a failed futuristic ideology, but a destructive anachronism. In this sense, Russia only joined modernity in the 1990s. Time heals all wounds.