A combination of several intersecting factors has led to a perception of Israel in the average voter's mind in the US as basically the ultimate safe haven of the Jews, so any attempt to pivot away from providing as much aid as they need looks like the abandonment of the Jews to a second Holocaust.

The average US voter is largely unaware of the absolute extent of Israeli crimes against humanity, among many other things that would probably otherwise earn Israel the reputation of a rogue state on par with apartheid South Africa or North Korea, what they are aware of is the history of antisemitic persecution that Zionists cite as what necessitated the creation of Israel, something that American Jews at the time actually rejected, but were basically overruled on in the cultural narrative due to Israel using a huge diplomatic lobbying effort to win over American political leaders in combination with the Evangelical great awakening in America fostering an independent christian Zionist movement that viewed the existence of Israel as crucial for the rapture to happen, nevermind how that book of the Bible itself declares that attempting to know the date of the rapture by any means is idiocy at best and outright heresy at worst.

In American politics, we have legalized bribery under a very specific framework called “lobbying”. These days, this is largely accomplished through “Political Action Committees”. Basically, it’s a group that gets together to push and advertise for a candidate, specific or related collections of isssues, and so on. The funding for these groups is, shall we say, not looked at too hard, and that’s by design (of the politicians, to be clear).

So, we quickly get into a position where Israel creates a behemoth of a PAC to push their interests in US elections: this is AIPAC. AIPAC has a shitload of connections to TONS of funding and influence across the political spectrum, and uses it very aggressively to support US politicians who are friendly to the current Israeli regime’s interests. Incidentally, they threw in with Trump in both 16 and 20, because as pro-Israel as Biden is, Trump is far more willing to just straight up ignore the concerns of Palestinians and their voters, since he does not care about them due to the fact that a) he is overtly racist, and b) almost no Palestinians or even Muslims are going to be voting for Trump, for obvious reasons, so there’s no quid pro quo for him to exploit.

Anyways: PACs can and do inundate the internet and airwaves with political advertising, and most of it is straight up propaganda of one form or another. And of course, media orgs lean into anything can be spun as controversial (because that drives engagement, which drives ad sales, which is profitable).

Also, I need to be clear at this point: this is not some oblique screed that’s descending into old antisemitic tropes. This is an indictment of an obviously corrupt political mechanism, and one of the particular entities that takes massive advantage of that corrupt system on a regular basis, often to our detriment (and, paradoxically, their detriment as well, in a long-term, strategic, and demographic sense).

Like the other commenter said, people have been ignorantly supporting Israel for decades. There are a lot of Jewish people in the US, even if they're not Israeli, they would have said they supported Israel if you randomly asked.

And Israel has a very large lobbying group in the US: https://en.wikipedia.org/wiki/AIPAC