As to the leading question I would ask: should white supremacy anger Jesus any more than any other tribal hatred?
And to, does it anger the church? I would ask did the sicarii movement in Judea anger the Jerusalem church? To which I would suggest not particularly because they felt no ownership of it. They would have recognized it as sinful and antithetical to Jesus' teachings and they did in fact see the conflict it ignited as a harbinger of God's judgment, and made haste to separate themselves from it by putting physical distance between it and themselves (Eusebius).
For me the predominant emotion is not anger at a miniscule Nazi or white supremacist movement which I see as a bogeyman. There are those whose interest is to pump it up as representative of a large segment of the American people but I believe that is false. My main feeling is a somewhat helpless fear that the hatred on both sides might draw others in and ignite into something more truly threatening. I say "helpless" because I am currently going round on FB with a cousin who insists that my concerns on this are no more than a deflection from the really important issue of racism.
But I really do worry that Americans are sleepwalking into a catastrophe. I see a noticeable growth in what I would call "gratuitous hatred", evidenced by a willingness or even eagerness to believe the worst of another person and impute evil motives to them in the absence of any evidence.
Gratuitous Hatred
(Heb. שִׂנְאַת חִנָּם). According to the Talmud gratuitous hatred is the most vicious form of hatred, and the rabbis denounce it in the most extreme terms. In their view the Second Temple was destroyed as punishment for this sin.
http://www.jewishvirtuallibrary.org/hatred