And talk about simpleton narratives, only a simpleton would swallow whole the idea that trump was just making a sincere plea for gathering and sharing expertise.
You are correct that it was a slight variant on "go back where you came from". His twist included a sneering challenge, the equivalent of "if you're so smart.." So he can combine a racist trope with a schoolyard taunt and that's plenty to disguise it for you. Sad.
Your interpretation of the 4 as "hating the US" stands in direct contradiction to their unwavering statement of love of country with a commitment to improve the US. "They hate the US" is another trope to "other" those who disagree with you. Would you like me to rattle off a list of a dozen ways in which Trump clearly hates our country? It's easy.
Only the gullible take polling data directly from Trump's mouth. The poll showed the 4 are unpopular with 'whites with less than 2 years of college'. Didn't bother to look that up, did you? They're as popular as ever - with those that elected them, and will likely do so again, so go back to hopelessness.