The support of the state for this evil can only be maintained by the consent of the governed, however this consent is achieved. In this context, "consent" and "consensus" are strongly intertwined.
I am not suggesting you tolerate racism or any other *ism. I am suggesting governance by consensus from manufactured consent *does*, or allowing one's self to be governed by the appearance of consensus, genuine consensus, manufactured consensus, or otherwise.
The problem with using "consensus" as a measure for social issues is problematic at the start for *any* grouping of people. It's a *human* issue, not a nationalistic one. The United States is not alone in this problem.