I'm not at all sure what the appeal is to those in power / American politicians to be used by Israel like they are. Just shallowly thinking one might assume it's some sort of anti Islam sentiment / post 9/11 thing. But at the same time the current administration has a lot of Islamic allies... so that seems like a contrast.
America's leaders are elected, and have routinely prioritized getting [re-]elected over our national interests (on every issue, domestic or foreign) for the past 2 1/2-ish centuries.
Regarding Israel, the history of that choice goes back to at least 1943:
In general, pro-Israel political groups understand this dog->tail relationship extremely well, have excellent political skills, and have been pouring resources into maintaining that status quo since WWII.
Vs. those who don't like the consequences of that dog->tail relationship are sadly unable or unwilling to play the political game at that level.
OR: Find somebody who's been around American political campaigns for the past half-century or so. Then ask him how 99% of Election Days work out, for candidates who are perceived as "insufficiently pro-Israel".
