The notion that “we’re all still Americans after all” is based on a fallacy. It presumes an “America” that no longer exists.
There are two Americas, and have been since the dirty hippies declared their Uncivil War in the 1960s:
calls for a unity among Americans that transcends left and right are either naive or disingenuous. America will be united only when one of them prevails over the other. The left knows this. Most on the right do not.
9/11 failed to “unite” the United States. This means nothing can.