Sadly, from what I understand in the US at least, anti-immigrant sentiment is often common among immigrants themselves after some time has passed. To be clear - I'm sure there's a lot of nuance that I'm not privy to, please don't read that as some strict assertion.

But for instance, from what I understand about the Cuban diaspora in Florida, they are often viciously anti-immigrant.

Just us humans being humans unfortunately, we got a lotta work to do on ourselves, collectively.