Israel claims to be the state representing Judaism as a religion and Jews as an ethnicity. Israel heavily lobbied for things like the application of the IHRA definition of antisemitism by allied countries. That definition is conflating anti-zionism with antisemitism, which means conflating all of Judaism with Israel.
So Israel is responsible for some antisemitism as its actions cause hate against Israel and Israel works to make this hate go towards all Jews instead. This serves to purposes. The first is to always claim antisemitism, when Israel is rightfully criticized. The second is to hold all Jews outside Israel hostage to support Israel and to make them less safe, so they feel like they need to support Israel as a “safe haven”.
Israel profits from antisemitism and antisemitism profits from Israel, which is why some of the greatest supporters of Zionism have been staunch antisemites. Finally when it comes to people being attacked as “antisemites” for criticizing Israel, these are disproportionately Jews. Jews that are against Zionism are a great danger for the narrative of Israel, so they take special care to attack them.
It is not the only reason. In swing states like Michigan it seems to have been the deciding factor.
https://www.newsweek.com/jill-stein-wins-22-vote-dearborn-gaza-stings-harris-network-1979861
However i doubt that even with a decent campaign of addressing the economic concerns of normal people the Democrats could have hacked it. With the steadfast support for Israel they have shown everyone whose ancestry is somewhere south of the European alps, that they are second grade people, easily dispensable if necessary.