I don't like talking about Donald Trump, but I have to say that I understand why he believes there were mass celebrations among American Muslims when 9/11 happened. To someone with his mindset, it just feels like it might be true. It's not surprising that people would step up to defend him, "remembering" these things that didn't happen, and desperately clinging to anything they can find, no matter how far-fetched or undocumented, that supports the position.
The conservative media are leading the charge to prove his position, going so far as to pronounce the pushback Trump has gotten to be the product of their usual bogeyman: a conspiracy of the Liberal Media.
But let's be honest: While there may have been very isolated examples of American Muslims (or non-American Muslims who happen to live here) celebrating what happened on 9/11, there were no mass celebrations, no swarms of thousands of Muslims dancing and celebrating in American streets. Such activities would have been documented in a lasting fashion; it would not be necessary to comb through news reports hoping to find nuggets of support.
The reason why we know this is because in the days following 9/11, the government began detaining Muslims, mostly men, whom it deemed to pose a threat to national security. These men were frequently held for long periods without access to family or attorneys, in undisclosed locations. In a political climate that would permit the *government* to engage in these decidedly un-American activities, it is simply not credible to believe that thousands of American Muslims could celebrate 9/11 so openly that Donald Trump could see them doing so on television, yet no video of those activities survives even 14 years after the fact.
The American Muslims I know were horrified at what happened on 9/11, not because of what they surely knew would bring retribution heavily down on them, but because what happened on 9/11 was a crime against all humanity, including themselves.
I have said it many times: The human brain is an amazing thing, capable of great intellect and reason, but dangerously capable of self-deception. Memory, particularly long memory, is untrustworthy, because it can be distorted by emotion and imagination. In one prominent example, many people remember the famous shower scene in the Hitchcock film Psycho for its vivid red blood, running down the shower drain. It's a shocking scene, one of the greatest in cinematic history. But the people who "remember" red blood in that scene are wrong. In reality, Psycho was filmed in black-and-white. In reality, the filmmakers used Hershey's syrup, which of course is brown. In reality, no one saw red blood, or red anything, in Psycho--but many people "remember" it that way.
Wanting to believe something happened makes it easier to "remember" it.
This is not a media conspiracy against Donald Trump. He is simply wrong about what he remembers. That's a human-enough error that can be excused on its merits. But what we should be more vigilant about is not the "what," but the "why." Why does it matter? What is the importance of "knowing" that American Muslims celebrated 9/11? If you falsely believe that they did, what are you going to do with that information? Are you using it to feed hatred in your heart toward people who have literally done nothing to you? That can't be a good idea.