There's lots of debate online as to whether the movie District 9 is racist.
The movie presents something like apartheid, but the despised minority (sic) consists of literal aliens, whose intellectual and leadership elite have been killed by some kind of epidemic. The South Africans in the movie (white and black) regard the aliens as vaguely threatening lowlifes, and there seems to be considerable justification for this view. The aliens actually look a bit like crayfish or something, which of course helps to justify their cruel treatment.
Then the human protagonist gets to know an alien who is a leader. We get to know that the aliens, at least at their best, had extremely powerful technology, including weapons, but used their weapons only for defensive purposes. Cruelty seems to have been literally unknown to them until the epidemic and crash landing. The leading alien freezes in horror when he realizes a human lab is torturing aliens, just out of curiosity. Modern science. There is almost a suggestion at the end that we deserve to be conquered by (presumably morally superior) aliens.
Some liberals are saying: there is still too much racism here. The aliens are presented as sufficiently grotesque that something like apartheid is more or less justified. Slate goes further: The protagonist gradually turns into an alien, and he is consistently horrified by this--he doesn't accept becoming an alien, therefore he doesn't truly accept aliens as no different, or at least no worse, than himself.
This is a nice statement of one kind of new liberalism. The real test of acceptance of "others" is a willingness to become just like them. Unless you pass this test, you probably don't want grandchildren who look like them either; therefore in your heart you oppose intermarriage; therefore if you find yourself with something like apartheid or Jim Crow laws, you might breathe a sigh of relief. Decent and intelligent people, if they simply don't want to see people like themselves disappear, might be defenders of racist regimes that are, with Hitler, the epitome of evil for many liberals.