I'll say it again: the Black Church is American Protestantism's Armenian Church.
The Armenian Church ceased centuries ago to be a missionary church and became nothing more than an adjunct of Armenian ethnic identity. After the massacres of the late nineteenth and early twentieth centuries decimated the Church what little theology that remained in it was snuffed out to be replaced by ethnic (often Leftist) political activism. Most Armenians do indeed seem to be on the Left.
The American Black Church was originally a real church, but the injustices Blacks suffered caused it to cease being a true church and to become, like the Armenian Church, merely an adjunct of ethnic identity. No telling how long ago this happened, either.
The Armenian Church has a liturgy that is the single most beautiful thing I have ever yet experienced in this life--an ancient liturgy in Ancient Church Armenian, heart-rendingly beautiful chants and music--yet there is no theology there.
The "liturgy" of the American Black Church is a "fundamentalist" one (lots of shouting, sweating, bellowing, Bible-banging, etc.), but the Black Church is obviously as devoid of theology as the Armenian Church.
Both are nothing more than ethnic identity clubs headed by militant lefties who don't really believe anything.
That's my opinion, harsh as it is.
This is an inaccurate generalization. It depends on the congregation. I am white, and through my friendships I've been to two large majority AA churches around here (Maryland's population is 1/3 black) and they both have calm, quiet ministers who don't rant and sweat, but rather teach the Bible, week after week.