The right has been vigorous and consistent in dehumanizing non-white migrants and portraying them as presenting existential threats to the US.
Now, large numbers of the US population view migrants as a threat and reject the notion of providing them with asylum.
This follows a similar pattern which resulted in many in the US blaming parents of migrant children for being separated at the border.
I haven’t seen polling, but living in Trumpland, I know that many people blame parents for the deaths of migrant children in US custody, support the gassing of migrants, and would likely support the use of lethal force against migrants.
The US mainstream media will only give short term superficial coverage to this issue. If the messages of dehumanization of migrants and rationalization of violence against them, are to be countered, progressives have to speak out,consistently, cogently, and passionately, to broad segments of the US population.