Turning back to the Jews, he continued, if there is a superior race, it's them. Whatever the world throws at them, they survive, and they thrive. After millennia of persecution, in whatever country they live, they are in the creme of society, among the most successful, most educated, most resourceful people. "But how can you say this, if you hate them?" - asked someone in the audience. "I'm at least honest about my reasons." - came the response.
I frankly don't remember a single thing from the book apart from this scene. It stuck with me for two reasons. One, it made complete sense. Two, only in fiction you find such compelling characters who are so clear-eyed about their moral shortcomings.
Thesis
But there are and always have been overachieving minorities. The prime example today is the Asian Americans who form the highest-income ethnic group in the US, earning well above the majority whites. The business elite in Vietnam was for a very long time dominated by ethnic Chinese. I've listened to a podcast recently that listed similar minority groups in Iran, Africa, and the Caucasus, whose names I heard for the first time, then forgotten quickly.
Why is it then that only the Jews have become the global bogeyman? I think the answer is the Catholic Church.
History - beginnings
In the early days of Christianity, the followers of Jesus were just one of the many small Jewish apocalyptic sects in historic Palestine. As small sects tend to be, they were persecuted by the religious majority of Judaism. After Christianity's improbable rise to be the state religion of the Roman Empire, the boot was on the other foot, and the "turn the other cheek"-part was put on the back burner. Unlike the pagan religions, the Christianity demanded exclusivility. The Church persecuted all other religions, but the Jews were singled out as its vilest enemies. First, it was payback time, and secondly, the believers of other faiths at least had the excuse of being ignorant. But in the Christian mind, the Jews knew the Messiah and rejected him. They were God-killers. The facts that the Old Testament is part of the Christian Holy books, and Christianity tacitly accepts that the Jews are God's Chosen People, and Jesus himself was a Jew, were conveniently put aside. There is no cognitive dissonance that cannot be suppressed.
I don't know enough about Islam to trace the roots of Muslim Antisemitism with confidence. But my guess would be that Islam and Christianity share a basis of animosity against Judaism because they both see it as their parent religion that rejected the final messenger from God - Mohamed - or God himself. To them, Judaism is much closer to heresy than being a completely different faith, like Hinduism, and heretics are always hated more than non-believers. On the other hand, the concept of God-killing was missing from Islam, and for many Muslims, both Jews and Christians were people of the Book.
History - medieval times
As mentioned above, the Christians were not so relaxed about these things, therefore in Medieval Christendom Jews lived under the constant threat of persecution, pogroms, or at least dispossession. They were not allowed to own land, to be part of the nobility, or to have a position in state administration. The paths of integration into respectable society were blocked to Jews, leaving only those professions available to them that were beneath a good Christian. Like finance, banking, or academic studies. Jews, whose culture has always valued learning and intellectual curiosity, proved to be very successful in these fields, which wasn't exactly the Christian intention.
In the Islamic Middle Ages, life for Jews was definitely better than in Western Europe for the reasons mentioned above. The Muslim religious fervor manifested itself more in conquering rather than in converting. The Muslims were much more tolerant towards other religions on the territories they controlled as long as the subjugated minorities paid their taxes and kept their heads down. But the popular concept of the golden age of Muslim tolerance is oversold. Minorities were second-class citizens without the protection of the law, at the mercy of the majority.
History - modern times
In the modern era, religiosity in the West has slowly receded. Modernity eroded the significance of ethnicity, birthright, and social status, and elevated the importance of education and intelligence. The ways of making a living Jews had been basically forced into earlier - notwithstanding that due to their traditional reverence for learning they had an affinity to -, like banking, law, and medicine, have become increasingly more important and more profitable. The old aristocracy of land was gradually pushed into irrelevance by the new one, the aristocracy of money, and it was disproportionately represented by Jewish families, like the Rothschilds. Religious animosity from the majority was increasingly replaced by material envy as the stories about baby-blood-drinking Jews were replaced by conspiracy theories of Jewish cabals secretly running the world.
From the nineteenth century, credit to these views was given by the fact that Jews were indeed overrepresented by the vanguards of ideological currents that turned the world upside down. Capitalism came first, which benefited those who held an already long tradition of being involved in finance, banking, and trading. Then Communism swept over Europe, which toppled the Christian regimes. Jews were in general disproportionally present among intellectuals, thus not surprisingly, even more so in anti-religious intellectual movements.
The Jews have been in the middle of another societal battle as well. Because of the prohibition of owning land and of their traditional professions, Jews have always converged to cities to ply their trades. The urban-rural political divide - that pitted the presumably unsullied people of the land against the decadent urbanites - always had a distinct antisemitic undertone. Furthermore, the Jews have stubbornly refused to fully assimilate.
But after the Second World War, open Antisemitism became a strong taboo in the West. Not in the Muslim world, though, where the creation and flourishing of Israel and its successive military victories over its Arab neighbors pushed them into a collective frenzy. Israel managed to defeat the combined forces of its enemies on the battlefield over and over again. Israel is a Western-style democracy, the Arab states are corrupt and incompetent. Israelis are living on Western standards (on the only land in the Middle East without oil), Arab citizens in poverty and oppression. Jewish Nobel-prize winners are a cliche, while the number of such scientists the Arab world has produced is exactly zero. The dissonance between reality and what Muslims think their rightful place in the world should be (being the receivers of the final revelation from God), is as enormous as the inferiority complex that follows it.
Matthew Effect
"For to every one who has will more be given, and he will have abundance; but from him who has not, even what he has will be taken away."
There is another factor that is so mundane that it can be easily overlooked. Every instance of publicly blaming Jews for something grows the history of Antisemitism. So the next time someone is groping for a culprit to explain away his or his tribe's failure, he can recall some antisemitic rumor more readily - this is called availability bias. He runs away with his instinct and the self-reinforcing cycle is closed. This I think is just the Network Effect, or as sometimes called, the Matthew Effect. From all the social networks available to them, people choose the ones where they can connect to the most people. From all the available conspiracy theories that explain a given state of affairs, all things being equal, we tend to choose the ones shared by the most. And conspiracy theories involving Jews have been around so long and therefore have so many followers, that they are now impossible to displace.
Summary
To summarize, Antisemitism is rooted at the foundation of Christianity. Jews have been initially persecuted for purely theological reasons, then forced into certain occupations for the same reasons, which by chance and with time have given them power that earned the envy and jealousy of the majority. They have become the perpetual culprit for any calamity or lack of success of majorities, even when the original reasons were no longer relevant. The image of scheming Jews is unerasably part of our collective psyche. As long as Jews refuse to die out or assimilate perfectly, Antisemitism will be always with us.