When they say things like this it indicates to me that subconsciously they don't consider black Americans as a part of the "American nation". Indirectly they are affirming the basic premise of black nationalism, namely that black people in the US constitute their own distinct nation. One which is imprisoned within the US prisonhouse of nations much the same as the indigenous nations. This in turn justifies the waging of a struggle of national liberation up to and including separatism.

Though of course the liberals who usually use these sorts of phrases are not thinking that far, they are just indifferent to history and to the implications of what they are saying.

From a historical perspective it seems to me that the USA was rarely so united. They came to the point where a significant number of black people engage in liberal politics. They have masses of nice and proper liberals defending wars, atrocities and the myths that justify them, despite the fact that their historical record is right behind them. They've got a majority of people antagonizing the new enemies of the State in a manner that is a lot more subtle than they did the USSR.

Maybe I underestimate the leftist movement but to me things look pretty good for them in terms of politics.

However the state of the empire is so dire that they are still beating the drum of unity, which is completely jingoistic at this point