I can easily see this #BarabooHighSchool photo op happening in the town I'm from in Iowa. (I know that many of the people there are Trump supporters.) Here's how I imagine it happening:
These kids live in an all-white (or almost all-white) community.
Nearly all of the non-white contexts and individuals they are presented with in their daily life come from the media.
Their media diet is controlled and regulated by corporate media conglomerates that allow propaganda mills like Fox News to run wild, while dictating exactly what words will be spoken on the local nightly news.
These media messages are not convincingly challenged by the films, TV shows, and literature that these kids have access to, which tend to present a South Park-ish "both sides"-ism as reasonable.
The only place where they are hearing about subjects related to "social justice" is through the lens of the internet anti-PC industry, which caricatures and demonizes the PC enemy. A boundary is drawn between "us": [normal.] and "them": [elitist. effete. insufferable.]
Because of a profound lack of real-world experience with non-white communities combined with the erasing/dehumanizing tendencies of the media they're consuming, the life experiences of people who aren't white just...don't seem real.
The Other, as it is constructed, is a white liberal intersectional feminist/cuck who loves calling people out with harsh, self-righteous language
This "us-versus-them" lends itself to a sort of playful hatred, like a sports rivalry.
It is this "playful hatred" that these boys are expressing. I'm sure there are boys giving the salute who will say, "I'm not racist!" and even believe it themselves. This is because in the context they're in, racism is completely normalized to the point of invisibility.
Is there hope? For any given individual with sufficient insight to grasp the contours of his situation, perhaps, but it's a difficult road that will probably get you disowned by your peers.
To acknowledge that this was wrong means to see and acknowledge the flaws inherent in the worldview of everyone around you, which is a strange and lonely experience. Even more difficult than admitting you were wrong.
Neither of these is likely to happen without the direct, concerted effort by those of us who know young people in these kinds of places to reach out to those young people and try to have conversations that counterbalance the other influences around them.
Because right now, every single thing around them is encouraging them to become fascists.