To begin with, I'd like to offer up a premise, which I think is rather intuitive but which I am open to hearing a critique of:
Human beings have a moral obligation to try and remedy unjust systems of which they are the beneficiary
I'm have warrants to support why this is true, but for brevity's sake (Lord knows I have that problem) I'll hold off on providing them unless the obligation is challenged.
So, for example, if I'm a monarch, heir to a throne established long ago, I have a particular responsibility to try and democratize my country, because I'm a key beneficiary of the current autocratic rule. If I'm a White southerner in 1900, I have a particular obligation to resist Jim Crow because I reap benefits from the current state of injustice.
This is actually a weaker claim than I could be making: I could simply say that human beings have a moral obligation to try and remedy unjust systems whenever they can. And perhaps I believe that, but I don't need to go that far in order to make my argument here.
There is an important clarification to be made. Saying "you have a responsibility to resist racism" is not the same thing as saying "you were responsible for creating racism" or even "you are an active participant in maintaining racism." If I'm told: "you're responsible for cleaning up the kitchen," that statement is entirely agnostic to what degree, if any, I'm responsible for causing the kitchen to have become dirty. There are all sorts of reasons why I might be responsible for cleaning up the kitchen even though I did not make it dirty. For my purpose here, I'm forwarding the argument that you have an obligation to assist in "cleaning the kitchen" (dismantle racial hierarchy, for my pet issue) if one reaps benefits from the kitchen being dirty (if one reaps benefits from the preservation of a racial caste system).
I cannot stress how important this is. In his post, Mark uses the rhetoric of "guilt" and "innocence", and says that I am tagging all White people as "guilty" of perpetuating the slave system. I am not. No living White person today is responsible for creating the slave system. They are "guilty" of nothing. They should face no moral opprobrium for the sins of their parents. There should be no Dickinson-style beheadings. Mark's ancestors could not avoid the "crime" because they did not commit one. However, the crucial point is that my argument depends not a whit on ascribing guilt to White people. The link to an obligation stems out of benefits one accrues from the oppressive regime, regardless of whether one helped create it or not. The divorce of responsibility for causing and responsibility for ending is critical--without it the argument makes no sense. I think a lot of people mistakenly equate the two and oppose it for that reason. I could, to be sure, condemn a White person for failing to actively oppose racism. But I'd be condemning him for failing to fulfill a moral obligation, not because he's a slaveholders grandson.
In the previous post, I made the following syllogism of how Whites benefit from past wrongs against Blacks, even if they or their ancestors had no role in establishing the harms:
A) We still live in a de facto racial caste system. This is supported by the fact that nearly every social indicator--controlled for class--has White people at a tremendous advantage over Blacks in virtually every aspect of life. David Roediger (American Studies/U. Minnesota) has documented "the wages of whiteness" that even post-civil war white people glean from the racial divide.
B) This caste system is supported, in part, by the immense network of images, stereotypes, economic deprivations, and other wrongs that flowed out of the slave system and reinforced the social hierarchy of white over color. This I think is obvious: if there is, in fact, a racial caste system, I don't think it's controversial that slavery has helped build it.
C) All White people today--regardless of ancestry--gain some benefits that flow out from the slave system.
Mark doesn't really dispute the premise that Whites are at an advantage in American life (which he can't, because the data is so overwhelmingly in my favor). He offers up a half-hearted response that since I believe that Whites benefit from a diverse social sphere, I can't then turn around and say that they also benefit from preserving a racial caste system. But that's clearly untrue: If I get $50 by beating someone up and taking their money, or $100 by working with him to build a new business, I'm benefiting either way (although I incur an opportunity cost for my injustice). He also questions my link to how slavery and Jim Crow have influenced modern racial stereotypes--but it's fairly easy to trace the development of both the Black sambo and the Black brute images to the slave era (see, e.g., George Fredrickson, "White Images of Black Slaves: (Is What We See in Others Sometimes a Reflection of What We Find in Ourselves?)", in Critical White Studies: Looking Behind the Mirror, Richard Delgado & Jean Stefancic, eds. (Philadelphia: Temple UP, 1997): 38-45). His main attack is that I'm ascribing group guilt to people who had no role in creating the original harm, but that's what my original moral premise is designed to address.
This is not supposed to be the last word, but the beginning. I hope that I've established my burden in subsequent conversations: if I can show that Whites are benefiting from an illegitimate racial schema, then I've proven that they have an obligation to end it.
Postscript: I apologize to Mark for consistently spelling his name wrong--with a name like Schraub, I sympathize. I also found interesting the story behind it--that "Olsen" became "Olson" to avoid anti-Norwegian prejudice and to sound more Swedish. Ironically, this may prove my point about modern import of injustices. Past prejudice against Norwegians was of course a very bad thing. But today, I'm sure Mark would agree it's played little to no role in his life. In fact, I could not even tell you the difference between a Norwegian and a Swedish name (it's all Scandinavian to me). By contrast, having a Black-sounding name does continue to have a major effect on one's life chances--not for the good. Sometimes society manages to move past it's wrongs. But sometimes the wrong remains ongoing. It's important to distinguish the two.