Steve Gilliard picked up on a post at Eschaton:

One of the media conversations I'm peripherally aware of (again, in this bubble I don't have the omniscient view of the media borg I usually do) is the "why do people call Obama black?" It's quite fascinating, really, that this is an issue. The same issue was raised when Halle Berry won her Oscar. I'll try to be kind to those raising the it, but they really seem to have a view of race as being genetic or "in the blood," which is, uh, a rather interesting view of race. The "one drop rule" still exists -- not because it's government imposed, but because if you look black people categorize you as black. Now, I look forward to a colorblind society but it doesn't exactly exist right now. Obama is black because people see him as black. The content of "black blood" in him is irrelevant. I highly doubt any of the people saying this didn't think of Obama as a "black man" before they discovered that one of his parents was white.

Steve's response:

Nope.

In America, there are two classes of people, white and not-white. If you are white, then you are white, but if you are not white, you are NOT WHITE. Have you ever heard of anyone described as half-white, unless they were visibly another race? No matter how pretty or how smart, if you are not white in America, you are not white.

…reminds me greatly of one of my own snarks:

Kind of a random thought that occurred to me while reading comments:

Division: White
Divisions seen: White, You-ain't-white

Division: Black
Divisions seen: Black, White, You-think-you're-white

Division: Everyone else
Divisions seen: White, I'm-as-good-as-white, Black

After the amusement passed, I needed to see for myself what kind of stupidity raised the issue, so I checked out the media conversation Atrios is peripherally aware of. The stupid question (which was amen-ed by another letter writer) was addressed there, and of course by Steve and Atrios.

But do you want to know the real, historical reason a person with a white mother and a Black father is considered Black?

That settled that, but it did not settle the legal question of who could be enslaved. And in 1670 the Virginia legislature spoke again on the subject, saying: "All servants not being Christians imported into this country by shipping shalbe slaves for life." Whether by design or accident, this law excepted blacks who had been baptized in Africa, Europe, the West Indies, or other colonies. But this loophole was eliminated in the act of 1682 which declared that "…all servants except Turks and Moores …which shall be brought or imported into this country, either by sea or land, whether Negroes… Mullattoes or Indians, who and whose parentage and native country are not christian at the time of their first purchase of such servant by some christian, although afterwards, and before such their importation …they shall be converted to the christian faith… shall be judged, deemed and taken to be slaves…"In plain English, this meant that all Jews, Asians, and Africans (except Turks and Moors) were subject to slavery in Virginia. It meant also that Virginia was embarking on the process (completed in the eighteenth century) of basing slavery on race rather than religion. (The Virginia legislature finally said that a Negro was anyone with one Negro grandparent.)

And that's not all:

Despite this fact, there was widespread opposition to the new order in the white community, particularly among poor whites, many of whom were still indentured servants or former indentured servants. What is amazing here and worthy of detailed examination is that so many whites openly flouted the new laws and conspired with blacks to evade them. How explain this? The explanation is simple: whites, in general, had not been prepared for the new departure. In the words of one white historian, opinion had not "hardened sufficiently" against black people. In the words of another, many whites "had not learned to hold the attitude toward the Negro" that the new script demanded. In addition to these purely passive considerations, there were positive and active links between blacks and white indentured servants, who continued to run away together and to conspire together. A point of considerable importance here is that slavery did not immediately displace white servitude. For more than one hundred years, the two systems existed side by side, mutually influencing one another. For almost as long a period, the white servant and the black slave continued to interact, threatening the stability of this dual system of servitude.

In order to preserve domestic tranquillity, the leading groups in the colonies made it a matter of public policy to destroy the solidarity of the laborers. Laws were passed requiring different groups to keep to themselves, and the seeds of dissension were artfully and systematically sown. Indians were offered bounties for betraying black runaways; blacks were given minor rewards for fighting Indians; and poor whites were used as fodder in the disciplining of both reds and blacks. At the same time masters used Draconian measures to stop the mingling and mating of blacks and whites. From the last quarter of the seventeenth century to the end of the eighteenth century, policy-makers legislated against these practices. In the process white women were whipped, banished, and enslaved to keep them from marrying black men. "The increasing number of mulattoes, through intermarriage and illicit relationships," Lorenzo J. Greene writes, "soon caused alarm among Puritan advocates of racial purity and white domination. Sensing a deterioration of slavery, if the barriers between master and slaves were dissolved in the equalitarian crucible of sexual intimacy, they sought to stop racial crossing by statute." In this instance, as in so many others, it was necessary to teach whites the value of whiteness. Under the ground rules of the time, a master could virtually enslave a white woman who married a black man and could hold in extended servitude all the issue of such a marriage. In this situation, as might have been expected, Puritan greed triumphed over Puritan morals, and many masters encouraged or forced white women to marry black men. It finally became necessary to pass laws penalizing masters for forcing white women to marry black men. The Maryland law of 1681 said:

Forasmuch as, divers free-born English, or white women, sometimes by the instigation, procurement or connivance of their masters, m's-tresses, or dames, and always to the satisfaction of their lascivious and lustful desires, and to the disgrace not only of the English, but also of many other Christian nations, do intermarry with Negroes and slaves, by which means, divers inconveniences, controversies, and suits may arise for the prevention whereof for the future, Be it enacted: That if the marriage of any woman-servant with any slave shall take place by the procurement or permission of the master, such woman and her issue shall be free.