Some people are racist, some people are misplacing their economic anger at immigrants when it was/is the capital/owner class who has disadvantaged them systemically, some people who are immigrants want to pull the ladder up behind them. My hot take, without going out and speaking to folks, (although I know journalists who are) is that there is a combination of regret between when POTUS said "we're going to kick out all of the immigrants" and what that looks like implemented (part out of sympathy/empathy, part out of self interested/selfishness due to personal impact).

A lot of folks projected their own mental model onto the campaign performance art, and those mental models are hitting reality. "Not like that!" broad strokes.

The US has historically run pretty hot and cold with immigration. We're in an "immigrants are evil" phase right now, and we have been before. But the wheel will keep spinning and we'll be in a "immigrants are great" phase again.

US' attitude towards immigration is generally correlated with how economically secure people are feeling. The less secure, the more immigrants are viewed as a threat and even scapegoated. What's happening with immigration right now says a lot about how secure people are feeling.