Where there is love and where there is violence, there's usually a power struggle, too. The fist in "Beale Street Love," and the love that it represents are powerful. There's no doubt about that. But is Clorinda powerful, too? She, after all, has the last word. There is physical power at work here, but emotional power, too. The question is, who has the upper hand?
In this poem, violence is a way to establish power in a relationship.
Though she may be abused, at the end of this poem, the woman seizes the power.