If you want to be this petty, this can be easily explained as american right not caring about Palestine specifically and simply hating him for other things. Please do not try to left/right this.
There is something crazy ugly going on on the left with all their 'happy he got an extremely painful cancer' that is not normal in American discourse and needs to have light shown on it. Please don't try to cover that up, it needs to stop/go away, or at the least be called out, not the calling out being silenced.