Recent trends in Jewish communal life are a lot easier to grasp once you realize that they're basically the exact thing going on across America, only Jewish (and so therefore distorted by our rather asymmetrical political distribution).
On the right, we're seeing a near-complete collapse of support for basic liberal and democratic principles coupled alongside increasingly bold flirtations with outright fascism. ZOA is the representative group here. A (very small) rump remainder of moderate conservatives is trying to resist this, to little success and functional irrelevance.
On the left, there's growing suspicion -- often spilling into outright antagonism -- towards "establishment" representatives who themselves identify as left-of-center but are thought to be hopelessly compromised. This, of course, is combined with more predictable loathing of the Jewish right -- because, again, the whole fascist-curious thing. The worry is that between the hatred of the right and the disgust towards the not-them parts of the left, the resulting politics ends up being reduced to inchoate, uncontrollable "burn it all down" rage. I'd say IfNotNow embodies this sect.
And then we get the Jewish establishment, which is more-or-less the center-left. Fortunately for it, the Jewish left-of-center establishment is considerably more dug-in than counterparts on the center-right, and so its ship does continue to sail -- albeit not without effort. On its best days, its representatives are trying to chart a course that both vigorously opposes the dangers of the right while not acceding to what sometimes seems to be essentially nihilist fury emanating from the further-left. On its worst, it engages in bland "both sides"-ism while practicing its best "Rome burning" fiddle routine. Does this describe, say, the ADL or the JFNA? I'd say so.
It's all obviously familiar, and yet standing in the middle, I somehow didn't really perceive the parallels. The major difference in the Jewish case is that there are proportionally a lot more left-of-center representatives, which alters how that branch of the conflict shakes out a little bit. But that has more impact on who is democratically legitimated to win the fight than it does on the fundamental battle-lines of it.
In short: What the Jewish community is going through right now is pretty much what America is going through, if America had backed Hillary Clinton by nearly 50 points.