Antisemitism in modern America is really tough to score. I think this statement from the article is fair:
Anti-Semitism must be fought, but on its own terms. This means not trying to fit anti-Semitism into the framework of other forms of bigotry. It's not racism. It's not classism. Treating anti-Semitism as its own axis of oppression—intersecting with others, but still distinct—allows for precision, and avoids over- or understating the case.
The "white" part of most American Jews' identity confers a substantial amount of privilege. The Jewishness part encounters prejudice, but it's different in form compared to what some other cultures see here in the US. I don't think Jews have the media portrayal problems, for instance. Economically they do extremely well, making something like twice the national median income, and they are the best-educated demographic in the nation. Jews are a model minority, like Indian-Americans or Japanese-Americans.However, there is deep-rooted antisemitism in our society, absolutely.
For me, I feel a bit of frustration at this article. It's an unfair frustration, but I think antisemitism is one thing in America that will turn heads and crystallize public opinion in a way that discrimination against blacks, browns, and Muslims does not. The ADL has actual teeth. If you run afoul of them they will fuck your shit up.
But Americans don't like Black Lives Matter. And they don't care about Islamophobic travel ban. (just two quick and dirty examples)
That's not the fault of American Jews. It's the fault of America as a whole.
We have all been taught from a young age that Nazis are evil. That's why it's so damn shocking that Trump couldn't get his denunciation right. It's much harder for Americans to realize, "oh shit, the Confederacy was also evil" or "oh shit, cops killing unarmed 12 year old black kids is evil too". That's closer to home and recognizing that takes a real gut check that I think much of white America can't do.
Anyway, of course
the left should stand united against antisemitism, and police it in our ranks when it pops up. American Jews represent a core liberal demographic and we should protect them too, not marginalize them or pretend that they don't face their own struggle with prejudice.