Kamala Harris got a much needed boost this week when the California senator picked up the endorsement of Higher Heights, the country's largest political organization aimed at electing black women.

But Elizabeth Warren would not be outdone. A day after Harris' announcement, the Massachusetts senator won the backing of more than 100 black female activists. She also picked up the coveted endorsement of Rep. Ayanna Pressley, a black woman from her home state and the only member of the so-called squad of progressive lawmakers not to side with presidential candidate Bernie Sanders.

The dueling endor...