I don't believe this claim, because immigration is a live political issue in my country (the United States) just as it is in Sweden; and people absolutely claim that reducing the amount of immigration the US accepts is immoral and genocidal. Seriously, claims of this nature are a huge amount of contemporary American politics and this is obvious to anyone who has seen the name "Donald Trump" in a news publication talking about the US in the past decade. Also I've read Bryan Caplan's argument that not having open borders is morally equivalent to Jim Crow, and read plenty of other people who think similarly to him.