Who is "Betting on the Dust Commander" - Lucius, Mare from The America Play, and Other Works and what is their importance?

Lucius and Mare are a married couple trapped in a cycle of violence, gambling (is it a coincidence that "Mare" is also the term for a female horse?), abuse and self-limitation, a cycle illustrated by the play's repetitive structure and dialogue. They represent and/or manifest the author's contention that African Americans are themselves trapped in a cycle of oppression-triggered self-violence, self-abuse, and again, self-limitation.