Here’s the basic idea of his book, Why the Jews?
http://www.dennisprager.com/so-were-hated/
“There are basically two possible ways to look at anti-Semitism. One is that anti-Semites are essentially decent folks and Jews have usually been so bad that they have merited anti-Semitic hatred. The second is that the Jews have generally been a decent people who antagonized many of the morally worst people of their time and place.
Anti-Semites would, of course, choose the first explanation. Others would acknowledge that those who have hated the Jews have usually been the vilest of their generation. Whether Roman torturers, Crusaders who massacred Jewish communities on their way to the Holy Land, Nazis or Communists — they all hated Jews. The monsters of the 20th century, the Nazis, made Jew-hatred the centerpiece of their ideology. And the monsters of our young century, militant Muslims, have done the same.
Why have the Jews, always among the weakest and smallest of peoples, attracted the hatred of the most evil people? Because of what the Jews represented. The civility of the Jews’ lives and the values the Jews brought into the world — especially ethical monotheism, i.e., a standard of right and wrong based on a moral and judging God — made them loathsome in the eyes of those who led particularly uncivil lives and who celebrated moral chaos and cruelty.”
There's another possibility that doesn't assume that one side consists entirely of Angels and the other of Demons.
The alternative explanation is that anti-Semitism has the same underlying causes as any and all other ethnic conflicts, particularly majority vs. minority conflicts. Whenever you have different religions, races, and ethnicities pursuing their collective self-interest and competing for wealth and resources in the same place, there will be mutual distrust and resentments. That's just human nature. If one of the groups engaging in the competition is out-numbered or out-armed, it will be at the receiving end of most of the abuse when the competitions, conflicts, and resentments escalate to violence.
The Jewish experience was mirrored by many other diaspora people: Hindus in Uganda, Armenians in Turkey, Tutsis in Rwanda, Chinese in Indonesia, etc. What Jews experienced is more familiar to us because it occurred in Europe, including Western Europe, rather than being a phenomenon of third-world countries.