I'd like to add in Travis' defense, he was an unknowing victim of the false narrative being portrayed by the media. Everything he conveyed about the incident in the OP was exactly as it was being delivered by the media. Even though we now know the portrayal has been proven as a false one, Travis is not to blame for the inaccuracies of the media and citing them in his OP. The piece targeted a specific group and the media raked in the $. It was very well played, though illegal.
Chris B.
I suspect there is also an element of a phenomenon that is far too common in America today, which is the "news island". So many Americans only hear news from the sources that are going to publish the news that their readers want to hear, with the bias that they want to include.
When Travis wrote the OP, everything in it came from sources which one may have expected to be reputable. CNN. The New York Times. WaPo. They all carried essentially the same information that Travis included. Some of it was slightly toned down or nuanced, but basically, they said the same thing as in the OP.
This was reinforced by visual imagery. The widely published still photograph seemed to fit the mainstream narrative perfectly.
For me, something didn't quite smell right about the story. I didn't think the behavior described was something I would expect from a Catholic high school group on a "field trip", even if the purpose of the trip was protest. On the other hand, it did fit perfectly with the sort of parody of Catholic high schoolers wearing Trump hats that might be peddled by anti-Trump news sources. When the people in a news story seem like caricatures or perfectly fitting stereotypes, I always get suspicious. When I saw the video, even the short clip initially published, I became more suspicious. Sandmann's expression included a certain bemusement at times, and the kids in the background seemed more like they were jamming to the beat than any sort of mockery. It was a little bit of disrespect and maybe some "cultural appropriation", but it didn't seem like a deliberate assault or deliberate ridicule. More like a touch of cluelessness. Nevertheless, nothing was so far out of place that it couldn't fit in with the narrative being pushed of racist Trump supporters being jerks, so the narrative was set in people's minds.
The longer video, and other evidence piling up, demolished that narrative, but here's where the "news islands" come in. The corrections and retractions, as always, weren't given the center stage attention that the original accusations had received. Unless you watched Fox News, or conservative outlets, you could easily miss everything else. Many people who post here are the sorts of folks who look for multiple sources, and who investigate stories that don't quite pass the smell test, but I'm guessing that Travis doesn't go to nationalreview.com very often. I'm sure there are millions of people in America who are sure that the story from the OP is completely, or at least essentially, correct.