As soon as I shared my last blog post on Facebook, a writer friend who had also lived on a kibbutz pointed out a glaring flaw in my Venn diagramming. The clues from Bernie Sanders’ brother and his professor friend can, in fact, all be true: Sanders’ kibbutz wasn’t necessarily founded by Argentinian immigrants; it just needs a significant enough influx of South Americans before 1964 to have made an impression on the young volunteer from Brooklyn.
So a revised Venn Diagram does have the potential for an intersecting middle: We should be looking for a kibbutz (likely in Western Galilee) founded between 1910 and, let’s say, 1936 that also accepted large numbers of Argentinean Jews—probably in the wake of World War Two or the founding of the state.
So far, going through the list of kibbutzim on Wikipedia, I haven’t found anything that fits that bill. Few of the listings enumerate where immigrants came from after the founding garin or group.
I did start a list of kibbutzim founded by Argentinean or South American groups before 1964:
Nothing that could be confused as one of the oldest kibbutzim in Israel….