It's worth looking at how that environment is produced too. There's a need for cheap labor in agriculture, laundry, hospitality and textile industries that dovetails well with the US's history of anti-mexican racism (grounded in the need to dehumanizing indigenous people to steal their land as well as the US-Mexico war).

By controlling people's movement through the border regime, we can make them willing to take sub-minimum wage jobs, while also keeping Mexico poor through lopsided trade agreements like NAFTA and low level insurgency achieved by escalating the drug war and flooding the country with weapons.

In this context of US oppression of Mexicans, it becomes necessary to dehumanize them to justify the violence. This is where fox news comes in. Hell, even CNN plays a role by creating categories of migrants some good and some bad, and playing them against each other while justifying border control (think about the rhetoric about dreamers vs drug smugglers).

To change this environment, we either need to undercut this propaganda by organizing white and brown workers together, or either take back control of media from big business or make our own media with similar reach.

Oh it's more complicated than that, but getting in to the psychology of fascism involves a lot of typing and there are more articulate authors who have already explained it at length.

it is that they live in an environment where they are told that Hispanic people are a threat, that caravans are "invading" the US to pillage it

They already hated brown people long before that.

These people don't have to be told a damn thing. They suspect the worst of the best, the best of the worst, and when it comes to 'others' they have nothing but scorn, even if it's completely baseless. It seems to be a kind of narcissism.

"Good people can't be good because I look bad by comparison. Bad people are good because I look good by comparison. Other people don't look like me at all and so we must assume the absolute worst..."

To be fair though, I don't know how we can sustain illegal immigration of low income workers.