The antipathy of the left towards Jews goes back a long way - from the time when they were seen as money merchants and were often more wealthy than the people around them, to their siding with the U.S. in the cold war and building up arms when the left was shouting for disarmament, to their struggle with the Palestinians. I do think that among some people on the left there is just a natural antipathy towards at least the Jewish cause, if not towards individual Jews.
The Soviet Union helped play this up during the cold war, as it was generally on the side of the Arabs and helped to build the Palestinian conflict into a major issue for the international socialist movement. The U.N. has been systematically used by anti-semitic nations as a weapon against Israel under the banner of ‘stopping racism’, disgustingly enough. And the extreme left supports this nonsense wholeheartedly, cheering every new U.N. Resolution condemning Israel for one thing or another while its (much worse) neighbors get a pass.
The plight of Palestinians became a major issue on the left, while much larger human rights abuses were ignored in other countries that did not have the same political impact. This happened in part because the Palestinian cause dovetails so nicely with other left-wing issues - antipathy to U.S. imperialism, the capitalism vs socialism struggle, etc. While the far left has universally condemned Israel for the plight of the Palestinians, other Arab countries persecuted or ethnically cleansed Palestinians from their own countries without a peep.
It may not be anti-semitism in the sense of hating Jewish people for their ethnicity, but then, a lot of anti-black racism isn’t strictly about ethnicity either - it’s the assumption that black people in the community will bring gangs and crimes and drugs, or that schools that admit too many black children will lower educational standards and become dangerous for their children, or whatever. Most racists have some kind of justification for their racism, and most don’t think they’re racist. Sometimes their racism has some shred of fact behind it, grotesquely twisted out of proportion.
Finally, you cannot call yourself a friend of Jewish people while calling for Israeli policies that would have the effect of obliterating the Jewish state. The fact is, Israel is surrounded by racist countries that actually do want to destroy the Israeli state and kill a lot of Jewish people and put the rest back ‘in their place’. Israel, on the other hand, is a modern democracy with human rights standards that has been pushed into its current situation by the hostility of its neighbors. It’s an island of modernity in a sea of ancient hatred and irrationality.
There’s a good analogy with the U.S.'s war on terror. Americans are good people who respect human rights, but terrorism has put them in a position where it is very hard to walk the line between morality and security. America has Guantanamo Bay, is firing missiles from drones into civilian areas, and just recently sent an assassination squad into a sovereign nation to kill an enemy leader. Had Israel done any of these things, the world community, including most of the people here, would be screaming for them to be stopped. Yet Israel faces threats much greater than what America has, and lives with the reality of rockets being launched into its towns and cities on a regular basis. It has been attacked by its neighbors multiple times since its founding.
I can’t imagine what America would do to Mexico if Mexicans were launching rockets into Texas, sneaking suicide bombers across the border to blow up American shopping malls and restaurants, and occasionally mustering armies to invade while maintaining an official policy of the destruction of the United States. My guess is that the U.S. would simply flatten it. As would most other sovereign countries facing that much external aggression from a neighbor. But Israel is supposed to be different somehow. And in fact, its responses to constant attacks and provocation have been far more muted than I would expect from most countries, but that hasn’t stopped its enemies from constantly criticizing every measure of self-defense it takes.
Israel is not expansionist. It has no designs on its neighbors. It does not export terror. If every country in the Middle East became like Israel overnight, it would be an area of peace and prosperity. So for Israel to be constantly painted as the bad boy of the Middle East is bizarre and inexplicable unless there are other motivations.
Racism is an insidious thing, and racists justify their beliefs in many ways. If you spend a lot of time feeling angry about Israel or you feel like marching to support the Palestinians, but you can’t give the time of day to the plight of the current victims in the Congo or muster similar outrage against what Syria is currently doing to its own people or what Iran and North Korea have been doing to their citizens for decades, then maybe you need to stop and do a little soul-searching about who the real enemies are in the world.
That’s three Presidents in a row who really weren’t concerned about the welfare of the Jewish people so much as political expediency.
But that’s not what Israel does. You’re mistaking Israel with apartheid South Africa.