"I realize that there is a large and often influential Jewish population in the US, and also that Israel is a strategic point and probably wouldn't make it without the aid, but why the support on that scale?"

Complicated question. I think you have to start with a understanding of the importance of the region- in terms of economics and miltary. Next is the religious significant (Jew, Christian, and Islam).
In terms of economic, there of course is the oil, but are other significant economic factors. First you at Europe's doorstep, next the Suez is sea route to Asia. This should lead you to consider the sheer populations which are involved- there probably is nowhere is the world in which is a focus of people and wealth- plus it is such a "unresolvable" conflict.
The fact that is seems so unresolvable, is the main reason that this problem as not focused on by American leadership- you are probably aren't going to get results and quite possibly get severely embarrassed. Paying a few billion has been a "cheap" solution to this problem.