I'm trying to word this in a way that doesn't make me come across as a problematic Gentile, but I think the Israeli Right is playing a dangerous game in that it constantly seems to attack the diaspora as lily-livered (or even self-hating) even though most of the diaspora are Zionists with affinity for the idea of the Israeli state. Israel as a state isn't supposed to be just "a country with lots of Jews in it" but act as a sort of representative of all Jewish people. I feel like a lot of Jews - not just the likes of Gerald Kaufmans or even Jewdas- are genuinely uncomfortable with Netanyahu becoming synonymous with their identity, especially as in certain countries the issue has become incredibly partisan.
What I am trying to say is that, for Israel to just not care about the diaspora would be an abdication of a lot of soft power. I would wager that most American Jews, if forced to chose between their affinity with the Democratic Party and a distant nation that implies they're a bunch of effette self-haters will probably go with the former tbh.
Diaspora Jews simply tend to have a completely different outlook on things than Israeli Jews. Being part or not being part of the Israeli story of "overcoming" diaspora and coming home is pretty decisive for one's worldview. And diaspora Jews are so integrated in their societies (and yet still very Jewish, otherwise this issue wouldn't have been on the table either) that we tend to adopt the framework of thinking prevalent in our countries and, more specifically, in our own "spheres" within these countries. At this point, the essence of what it means to be Jewish has become something completely different for different communities.
Which is all fine. But when push comes to shove, I won't be there getting dressed in a uniform and going to the Gaza border. Might post something on FB about it from my comfortable chair here in Europe, but that's about it.
I agree that American Jews are likely to pick the Democratic Party and liberalism over their support for Israel. It's even inaccurate to say they pick liberalism over Judaism, because everything they do fits with their understanding of being Jewish (which is terribly wrong and dangerous imo, but that's irrelevant). But this rift precedes Netanyahu and will be there after him, as it is rooted in completely different types of thinking. Netanyahu exacerbates it by explicitly teaming up with the Republicans, which was perhaps the most foolish move in his political career seen from an Israeli national interest perspective. But I think it is inevitable in a world in which politics is increasingly defined by the battle between those who think globally and want national identities to be fluid on the one hand and those who think nationally on the other hand. The U.S. is almost bound to be on one side given its history and demographic makeup, Israel is bound to be on the other side given its history and its challenges.
I think an Israel based on the Israeli understanding of what it means to be Jewish is more important than the soft power (which I think is overstated in the first place) that comes from not alienating left-wing American Reform Jews. I don't think Israelis should compromise on these things with Americans, as Israelis have to live with the consequences and these are fundamental issues.