While this sure as shit sounds like the original post was retarded Storm-Fag bait, it really is okay to actually answer questions honestly.

Ethnic and religious differences bred resentment when you govern those different ethnic and religious groups differently. The jews can't own land or cattle so they can't have asset wealth (so no intergenerational social mobility), but the gentiles can't issue loans past 3% (so no fast wealth building at all). Then the rulers take jewish loans to fund their building projects, vanity projects, and military expeditions; but can't pay them back at the interest rates they took (you can't print money when you're currency is a gold/silver coin). Now some rulers are protecting jews, and others are targeting jews. Some rulers realize they don't want to pay back the jews and expel them (selling their property to their clientele class). But for other rulers, the jews are a clientele class, and invite them back in, or make what amounts to Red Line districts that they can live.

Honestly, I think this quote from "The Jews of Kolin" website I found is pretty funny, and apt as a summary:

Another incident happened on the 8th of August. The Jew Izák Hauser was herding newly purchased oxen to the town and caused substantial damage to an oat field. Because of this, he was arrested and imprisoned by the mayor. When regent Gryzl heard about it, he summoned the mayor again and snapped at him: “You shall release Hauser immediately and I forbid you to command the Jews. They are in my jurisdiction! Immediately return the fines they paid for trading with salt because they have the right to trade salt and grain! The Jews have their privileges, you can go look for yours in a deep well.” The Kolín councilors were not going to tolerate this and sent messengers Jan Kršek and Šimon Večán to the under–chamberlain Přibík Jeníšek from Újezd who had been residing at his castle Březnice. They did not achieve anything as he referred them to Count Lichtenstein, to whom regent Gryzl owed his allegiance. Hence the councilors ordered the town scribe Jiřík Šebastián to write a supplication to the under–chamberlain as well as to count Lichtenstein. This angered regent Gryzl, who said on the scribe's account: “The beast Jiřík really gets my goat! I have to take revenge on him for his supplication against me.”

"No! They're my jews! Go away!" really shows how jews were kind of just being used as paws by elites to get money; and then either they would privilege jews different from the rest of the population, or jews would be targeted by those elites rivals.