A recent Pew opinion survey showing 79 percent sympathy for Israel over the Palestinians among Republicans versus a mere 27 percent among Democrats has aroused a furor in pro-Israel circles. But this sort of ratio has been around through the twenty-first century with little change.
By way of proof, note the 13 opinion surveys I collected between 2002 and 2018 at a blog titled "Republicans and Democrats Look at the Arab-Israeli Conflict." Arraying the surveys together (carefully done by my researcher, Delaney Yonchek), one finds that attitudes remaining consistent within specific bands. Favorable Republican attitudes to Israel range between 59 and 84 percent, averaging 73 percent. Favorable Democrats attitudes range between 24 and 64 percent, averaging 44 percent.
Yes, the 2018 Pew poll does show a wider gap than ever (52 percent), but Republican pro-Israel sentiments have been higher and Democratic pro-Israel views have been lower, so it's well within the 16-year range.
In other words, there is no dramatic shift in outlooks. The pattern of far more positive Republican and less positive Democratic attitudes has been in place for many years. Nothing has happened of late to suggest this pattern will end. Obama and Trump have both done their part to confirm this trend.
It's also worth a look at attitudes toward the Palestinians. Republican sympathy toward them is vanishingly small, from 1 to 16 percent, with an average of 8 percent. Democratic favor ranges from 9 to 27 percent, averaging 18 percent – not exactly a huge number.
Assuming the two parties have about the same number of supporters, ignoring Independents, and averaging their totals, one gets 59 percent of party members favorable to Israel and 13 percent favorable to the Palestinians, a 4.5 to 1 ratio. That in turn fits the average over the decades as established by the Gallup poll.
I'd say Israel stands in good stead in the United States. Yes, it could undergo a collapse of support such as happened in Europe in the aftermath of the Venice Declaration of 1980, but so long as conservative support remains inconsistent, this remains a distant prospect.