The Isreali Jews are indeed one of the most successful minority in the United States (alongside Irish and Scots, which have managed to produce presidents, as opposed to Jews, by the way) and that might have some attachment.
However, there are many other major issues, in my opinion.
First of all, Israel is seen as an island of stability in an important, troublesome area to US interests. America has other traditional allies in the region, such as Saudi Arabia, Jordan or Egypt. However, in all these countries, it is the non-democratic regime that is allied to the US. If you ask a fellow American, where would they feel the safest should the government change or should they be far away from the local government loyal security forces – Israel, Egypt or even Saudi Arabia – the answer would be without any doubt – Israel. It is a much better idea to ally yourself to a country which it’s democratically elected governments view America as it’s the greatest join than counting only on dictatorial regimes.
Also, the fact that there are many prosperous Jews in the United States work both ways – many Israelis have American family relatives and many American Jews give charity and do business with Israeli Jews – meaning the US has very good leverage on its ally. Should the Saudi royal family be toppled down – all the economic ties created in the last 7 decades with that regime will disappear overnight. Should Bibi go home and be replaced by a Labor party candidate? Nothing changes.
There is also the matter of sharing values. Americans see their values, such as personal freedom, universal suffrage, rule of law, etc. as the very soul of their country and constitution. Their governments used these values as justifications to go to war on almost every single case of war in American history. Israel is the only country in the region where you have these same rights, no matter what hardships our country has been thru during the past 70 years of our existence. The American people recognize this – and they expect their government to support such a country.
Also, it is an American core value that if you work the land, you deserve the land. While not relevant to today’s mostly industrial American market, this is what the founding fathers believed in, and it is the way America was built and developed.
Israel was founded by persecuted people which fled tyranny and have “bloomed the desert” – sounds familiar? This is why, especially in rural areas in the United States where agriculture and these sort of values still matter (that is where about 45% of the American people still live), support for Israel is strong. American elected governments reflect that.
Of course, don’t neglect economic reasons. America’s no. 1 export is weapons. Israel is an excellent purchaser of these products, but more so – because of Israeli legendary survival skills in face of almost impossible odds – i.e. coalition of multiple Arab armies backed up and equipped by a superpower (the USSR) couldn’t defeat us in several wars – it’s also great PR for your industry when everyone on the market know the IDF uses your planes, guns and equipment. Selling or developing weapons with the Israeli defense industry and IDF gives your weapon credibility and a certain prestige you can’t find elsewhere. So, ironically, the fact that Israel doesn’t have peace actually helps America to some degree.
And of course there is also the religious aspect – many Americans, especially on the right, have a religious reason to support Israel. And despite the fact that in the United States there’s a separation of church and state, these tendencies get reflected in their votes as well – if you want to get their vote, you have to support Israel.
For example, the Evangelical Church has some 80–90 million dedicated followers in the United States. That’s about 20–30% of the population – a substantial minority.
And while they are famous for their support of Israel, they are not the only denomination that holds Christian Zionist views as its official church policy.
As you can see, it has very little to do with how rich/famous or successful Jews are in America. Of course, it helps.
But I don’t think it is the main reason.