An interesting bit of history, but Cataneo repeatedly expresses (feigns?) a kind of disbelief that people who claim to be feminists could also be racists. This is especially confusing because she also explains exactly how it's possible.
"But what’s shocking and disturbing is the fact that in the course of crusading for white supremacy, some members and chapters of the WKKK also espoused an apparently contradictory commitment to both progressive politics and feminism."
"In this darkest, most insincere version of empowerment feminism, the WKKK promised women the chance to assert their newfound political power, to live life outside the confines of the home, and to exercise autonomy—some women even rebelled against their husbands or divorced them to join the WKKK."
"[...] these women claimed to see no inconsistency between their racism and their zeal for Social Security benefits and equal pay."
The final of these is followed immediately by: "Perhaps the WKKK did want to elevate women in society—specifically, women who hailed from their culture, who looked, acted, and thought like them."
Isn't that pretty clearly the answer? It's easy to see no contradiction there, as long as you think the only people worth considering are people like you. If you imagine a world consisting solely of WASPs (which is what the world looked like, for many of these people), then the kind of feminism espoused by the WKKK looks pretty universal.
You don't have to go as far as the WKKK to get that kind of result. You just say: "Of course women of color have problems, but insofar as they're problems related to being women of color, they're not our priority. We should focus on improving things for women as a whole." And now you've neatly defined "all women" to be approximately equivalent to "white women", and you didn't even have to put on a silly costume with a pointed hat.