Actually, the left, the ultra-lunatic-left, doesn't hate Israel. They hate America. They hate capitalism. And, they hate anything and everyone who has any kinship with America or capitalism. The left's hatred of Israel is incidental.
What is puzzling is why so many Jews in this contry lean so far to the left. There are Jews in entertainment and in labor unions (New York City teachers' unions) who lead the "Blame America First" efforts and this is puzzling.