The offical stance of the Church for centuries was an antisemtic interpretation of certain NT passages, helped by Paul’s antisemite passages in his letters. Yes, Paul was Jewish, as was Jesus. That doesn’t matter, because it’s not about logic.
When the Gospels were written, the writers had a lot of conflict with the Pharisees, who argued about what direction Jewish faith should take. After the destruction of the temple in 70 AD and the dispersion of the Jews, this was very important. Before, those Jews and Gentiles that believed the Jesus was the Messiah/ Christ were one sect among others, no problem. Afterwards, they threatened Jewish identity (esp. by taking in Gentiles, but not keeping the Laws - see Peters dream in History of the Apostels) and Jewish theology, so arguments got heated, and finally, the Jews kicked the Christians out.
So in order to justify themselves, the writers put retro-activly a lot of anti-Pharisee words into Jesus mouth, to convince everybody that Pharisees were false hypocrites, and they, the Christians, real believers.
And, at first they tried convincing Jews, but then they tried convincing the Romans - slaves and poor, certainly, but also normal citizens. So they tried to shift the blame from “Romans killed our God” to “The Jews did it, which we don’t like, anyway”. This is why Pilate is so reluctant in the Gospels, unlike what historians think.
A few centuries later, the Church has gone from persectued minority to major status, and most Christians have no longer any connection to Jews, they come from Gentiles. So a temporal account of intra-tribal struggle between Jews of different kind is read as permanent indicment of all Jews through all history. And that phrase Jesus says in one of the accounts “My blood will come over you and your children” and the answer of the mob “Let it come” makes it “okay” to persecute Jews, who are still persistent in denying the truth, which threatens the conviction of the group. After all, if there is only one truth, but some people don’t accept it, they either know that what you believe is not the real truth - which can’t be possible, OMG! - or they refuse from malicious obstinance/ because they are devils children.
This basic “logic/ explanation” then gets dusted off every time a group of Jews becomes richer because Christians are forbidden from lending money, leaving only Jews to do the necessary financial stuff that states need and so on.
Theology subjugated to a cause is never very logical. Look at Cecil’s column about how that bit of Noah drunk after the flood was used for centuries as justification for the enslavement of blacks - makes no sense now, because it’s circular and illogic, but was accepted back then. Similar this argument about the Jews.