Just to add to Tom Byers's excellent post on teaching _Birth_,
 for my class on war and popular culture, I was able to make
interesting comparisons between the conflation of race with rape (saving the
purity of the white virgin from the "brutal black buck") in _Birth_, and
the Bush administration and the media's description of the "rape
 of Kuwait" by Saddam Hussein to justify military aggression.  So I'm not so
sure about those 90s standards of racism.
I just read an article by Ella Shohat in which she makes a similar
connection, pointing to a picture in _The Sun_ accompanying a report on the
Gulf that is "very similar to the picture at the end of _The Birth of a
NAtion_.  She argues that "The rescue of white or dark women from a dark
rapist is basic for most colonial narratives, whose conclusion is the
assertion of patriarchal and imperial world order.  The historical
oversexualization of Blacks and Indians continued in the image of Saddam and
the Arabs."   As I recall, the Gulf War had a great deal of popular support
which suggests that our standards of racism in the 90s were not high enough
to subvert the rhetorical conventions of the racist "rape and rescue"
scenario.  Ella Shohat, "The Media's War" in _Seeing Through the Media :The
Persian Gulf War_ Rutgers 1994 147-154.