OVER the weekend the Democratic-affiliated polling organisation Public Policy Polling (PPP) came out with a survey showing that 21% of likely Republican voters in Alabama, and 29% of likely Republican voters in Mississippi, think interracial marriage should be illegal. (It also found about half think Barack Obama is Muslim, and that most don't believe in evolution.) Michelle Cottle of the Daily Beast, who hails from the South herself, thinks PPP is unfairly singling out southerners for these questions.

[T]his PPP report has all the earmarks of a poll taken with the specific, if perhaps unconscious, goal of confirming all of the nation's very worst biases about the South. So an average of 1 in 4 respondents still can't get with that whole ebony and ivory thing. Appallingly racist? You betcha. But can someone please explain to me what this has to do with the current Republican presidential race? Discussions of gay marriage I understand. But interracial marriage—since when is this a relevant topic in American politics? Similarly, why do we need to know respondents' views on evolution? Last time I checked, not even Santorum was waving the creationism (or intelligent design) banner in this race. Which could explain why, when I went back and looked through the rest of PPP's polls from this year, I couldn't find any other states that were asked about evolution. Ditto questions about whether Obama is a Muslim. And in only one other state did I see voters being asked about interracial marriage: South Carolina. (Surprise!)

Ms Cottle isn't saying that PPP worded its poll in order to bring out the most racist possible answers. (The question they asked is pretty straightforward: "Do you think that interracial marriage should be legal or illegal?") She's just saying that these questions wouldn't have been asked in any other region of the country. And it's true: we don't know the national base rate reply for this question. So we should look for other polls that compare attitudes towards interracial marriage in Alabama and Mississippi, or in the South more generally, to those elsewhere in America.

Let's start with this Gallup/USA Today poll last August.

Unsurprisingly, the South shows the least approval of black-white intermarriage of any region of the country. And Republicans and conservatives are less approving of black-white intermarriage than Democrats, independents, moderates and liberals. A poll of Southern Republicans is sampling the most anti-interracial-marriage political group in the most anti-interracial-marriage region of the country, so it could be expected to find levels of disapproval of interracial marriage that are higher than the ones shown here. And it did. How about Alabama and Mississippi specifically? Let's turn to last month's Pew report on interracial marriage in America, which breaks down actual intermarriage rates by state. From 2008 to 2010, 15% of all American marriages were mixed-race (where the races are white, Hispanic, black, Asian and "other"). The states with the lowest rates of interracial marriage were as follows: 1. Vermont (4.0%)

2. Mississippi (6.2%)

3. Kentucky (7.1%)

4. Alabama (8.1%)

5. Maine (8.2%) The salient point here, obviously, is that Vermont and Maine are 95% white and 1% black. Mississippi is 59% white and 37% black. Alabama is 69% white and 26% black. (Kentucky, incidentally, is 88% white and 8% black.) The reasons why Alabama and Mississippi combine such racially mixed populations with such low rates of racial intermarriage are obvious and familiar to any American. These are extremely segregated states, residentially, economically, culturally and politically, and that segregation both produces and is produced by high levels of racial prejudice.

Ms Cottle's complaint is that this isn't news. Why are we polling on this question? What is the relevance to the Republican presidential primaries? This is partly a fair question, and partly not. On the one hand, it's certainly true that one reason results like these make newspaper headlines is that they allow northerners and westerners (especially westerners; that's where interracial marriage is most common) to feel superior about themselves, and look down on ignorant hicks. On the other hand, the fact is that higher levels of racial prejudice and resentment in the South are real and politically relevant, and pretending that political contests these days aren't affected by racial attitudes is a form of deliberate ignorance that warps our political discussions. Republican voters in Alabama and Mississippi are choosing the candidate who they feel most effectively embodies their opposition to Barack Obama and today's Democratic Party. What is driving these voters' visceral dislike of our biracial president, the child of a mixed marriage between a white woman and a black African? What makes them uncomfortable and angry about the direction the country is heading? Who are these voters, what are their worldviews, how are we supposed to understand the messages they're sending through their votes? Do they think the government should intervene to enforce traditional sexual mores, even if it infringes on personal liberty? Which of the Republican candidates does that sound most like? To interpret what you're looking at when you read the Republican primary results out of these states, these are all things you have to understand.

By the way, can anyone guess which state has the highest rate of interracial marriage, at no less than 42%? Hint: Barack Obama was born there. Though if you're a Republican voter in the South, there's a good chance you don't believe that either.