Just "seems"!? Name me a recent US president or candidate that wasn't very pro-Israel. JFK is the only one I know and he got a bullet in his head.
Then you have the fact that about 80% of congress are AIPAC members. That alone tells you everything.
Then at the debates for NY mayor elections, all candidates were asked insistently if they support Israel and if they'll visit the Holy City as if it were a requirement, which is a very weird purity test for a job that has nothing to do with that.
So I don't know how Americans can look at these facts and still deny that Israel is not running their country or at least having controlling influence over their political system.