I loathe having to talk about Jesus, so much that I’ve literally been putting this off for years, but the "Jesus was Palestinian" movement is one of the most egregious and insidious examples of a genre of Jewish erasure that claims Jews are just a religion, not a people, and does this through an avenue of attack that the strategists behind it know that Jews prefer not to engage.
Second Temple Jews were ethnically JEWS. They lived in Judea, under a Judean King or King of the Jews (the Herodians at the alleged time of Jesus) and a Jewish court system. They aspired, as devout Jews do today, to a Jewish Messiah who would come and liberate them from oppression, who would come from the old line of David, the King of Israel.
According to the Christian story, Jesus claimed to be this Messiah, and Jews have been killed for thousands of years because we rejected this claim. That is, we rejected his claim to be our King, the King of the Jewish people/nation, because it didn’t mesh with our own prophecies about what that King would do. And because we rejected his claim to be our King (not the King of the Palestinians), we were murdered in large numbers every year. And the devout among us continued waiting for the real King from the Davidic line who would liberate us from oppression.
This sort of historic erasure is dangerous, violent, and wilfully ignorant, substituting things that feel good in the moment for reality. I don't care how good you think your cause is; this is never OK. Find a way to advance your causes without attempting to destroy the Jewish people in the process.