Zionists don't control American foreign policy any more than does motherhood, apple pie, or General Mills breakfast cereals --- they are all just things that the American public is aligned on. Israel enjoys broad support in both parties, and that's in part because the voters of those parties support Israel.
Except unlike all of those things, explicitly Zionist organizations spend millions of dollars lobbying and campaigning. For example, AIPAC alone has spent almost $2 million to unseat Jamal Bowman in his race against George Latimer, whom AIPAC themselves recruited. [1].
“Controls American foreign policy” is hyperbolic; I don’t think support for Israel would just collapse if those orgs vanished. But come on, comparing Zionism to “motherhood” and “apple pie” is disingenuous.
That's a weird thing to oppose considering most parties see the control running exactly the other way. The US needs Israel more than Israel needs the US.
Honest question: why does the US need Israel? Or, to put it another way, what concrete help or advantages has Israel given the US over the last few decades?
Even in the (ill-conceived and disastrous) Iraq and Afghanistan wars other ME nations produced a lot more help than Israel did.
More complex answers involve having an allied county in an area with a lot of Russian influence.
The history is long and complex, but keep in mind Israel ran all by itself for decades, and defended itself in multiple wars, without any US help. It was when Russia started helping Egypt that the US recruited Israel. It was not the other way around.
For a while when Russia seemed powerless people started questioning the relationship, but after Ukraine it was re-energized.
Other answers are cultural: Israel is very similar to the US and Europe, same equal rights for citzens, same democracy, same culture of freedom. And the US is allied with all countries that are similar to it.
Nothing would happen. Israel has defended itself from multiple wars without US help, if anything Israel's enemies are weaker than they were in the past.
Weirdly enough it's actually Israel's enemies that benefit from the US - without the US Israel would just do what it needed to to stay safe, and never mind if the other country is hurt. Israel would not care, because their own security comes first.
With the US Israel is like "fine, we'll do the bare minimum".
This is also why all those people who what the US to stop helping Israel are so incredibly foolish. If Israel felt less secure they would fight with even greater ferocity. If you want Israel to stand down make them feel very very secure.
First, there's $330b of financial support since 1946. Access to advanced weapon systems since 1962. Crucial intelligence + diplomatic support in all the big wars (56/67/73); crucial munitions support, and an offer to send a large numbers of ground troops in 73. Solid and almost unquestioning diplomatic support (or acquiescence) of essentially every action Israel has taken since 67 (no matter how provocative or ultimately detrimental to its own interests), backed by the assurance of automatic UNSC veto of course.
In the current operation, you've got 2 carriers parked offshore along with other assets in the region; special access to fuel depots and arms caches (that even Ukraine doesn't get); technical support from U.S. companies like Google, etc.
The idea that Israel fights its wars "without US help" just ludicrous.
Meanwhile, in return -- Israel just doesn't provide all that much. The U.S. supports Israel mostly for ideological regions (such as the kindling that it provides to the apocalyptic fantasies of the Christian Right) and to please other domestic political constituencies; and yes, out of a legitimate sense of moral responsibility since the Holocaust -- but not because it really needs Israel to be around (in the sense that it needs the UK, Germany, Japan, etc). It objectively needs countries like Sweden and Turkey more than it needs Israel.
Completely cut off from U.S. aid -- it would survive of course, but under significantly diminished circumstances. In particular it would have to give up the Greater Israel project -- which it of course needs to do anyway, but it would have to do so much sooner, and in an abrupt, violatile way leaving it in a much less secure position than it would like to find itself shunted into.
If you want Israel to stand down make them feel very very secure.
This is of course the mantra we've hearing since 67. And which brought us to the place we're in now.
If I had to guess, I suspect they might mean "opposition to Zionist control of American foreign policy" rather than "opposition to Zionism".