America's support for Israel is mostly a matter of our domestic politics, and in particular domestic political campaign financing.
On the Democratic side, it's estimated that fully half of campaign contributions from individuals come from Jews. Not all Jews care about support for Israel very much, but that fact probably gets glossed over when those that do talk with politicians.
On the Trumpublican side, support for Israel arises largely as something that might draw campaign funds away from Democrats or as an evangelical Christian issue ... and I would bet a lot of money that many of the evangelical Christians who made Israel an issue for their flocks were paid, one way or another, to do so.
The news media is also very pro-Israel. Several years ago some print journalists told me over a beer that the owners of most major newspapers made sure Israel got favorable treatment, and it is readily verifiable that the extent of American aid to Israel -- almost every year our biggest recipient of foreign aid -- very, very rarely gets mentioned. If you only followed American mainstream news media, you would probably believe that America is a neutral outsider in the Israel-Palestine dispute.
And CNN is flatly a pro-Israel news organization.
So while America definitely enables Israel's crimes, it does so in large part because it has been manipulated into it by a relatively small portion of the population.