I believe that it is truly wrong to allow such disgusting sentiments to be aired unchallenged. Still, I'm going to exercise my own privilege and not challenge them (on the threads, at least).
It is depressing in the extreme to see the White Citizen's Councils of the Internet on local blogs. I'm not unaware of local attitudes (although my own white privilege means I hear them less and their direct impact on me is minor). But the acceptance of such attitudes as valid - that they are a reasonable, if extreme, argument to make - revolts and surprises me. And I do believe that the caterwauling of extremists provides a nurturing environment for less hatefully stated, just as destructive racialist attitudes to grow.