As a Democrat, Louisiana Senator Mary Landrieu is running up against the late stages of partisan realignment. But while the rise of the GOP in the South may end her political career, nobody has ever confused Landrieu for a political neophyte, or accused her of misunderstanding the essence of Louisiana politics.

It’s against that backdrop that she attributed President Obama’s unpopularity in her state, in part, to the fact that “the South has not always been the friendliest place for African Americans.”

As regional or cultural dog whistles go, this is significantly less contestable than, say, the GOP's incessant derision of northern and coastal “values.” But it has provoked a backlash, not just from conservative pols and operatives who have created for themselves a state of denial in which racial politics don’t really exist, but also among professional political analysts, who believe Landrieu made an error by alluding to the South’s racial history in public.

Halperin caught some righteous flack on social media, both for cheapening the truth and for dinging a politician who, at worst, was willing to be candid against interest.

But the truth is, I think Halperin’s political analysis is backward, too, and that Landrieu's candor came in the service of her political interest, not against it. His assumption that U.S. politics tends to everywhere favor a willful blindness to racial history is commonly held. But it reflects a dated, '90s-era sense of the partisan tilt of the culture war.

Landrieu was first elected to the Senate in 1996. Then as now, Louisiana had a large black population, and Louisiana’s black voters, like black voters everywhere, voted overwhelmingly for Democrats. If anything, the black vote is even more reliably Democratic in Louisiana today. But at the same time, white voters in Louisiana have become much more Republican. Twenty years ago, it might not have made sense for a Louisiana Democrat to be frank about the region’s troubled racial history. Democrats won in the South by forming uneasy coalitions of black voters and conservative white Democrats who didn’t take well to criticisms of Southern political history and culture.

In 2002, Louisiana re-elected Mary Landrieu, even though whites comprised over 70 percent of the electorate. She was re-elected in 2008 by a modest but comfortable margin, in large part because Obama’s candidacy changed the composition of the electorate. Whites fell to 67 percent of the vote. Blacks climbed to 30.

Her calculation has changed. Today, if the midterm electorate resembles the 2002 electorate, she will probably lose. If it resembles the 2008 electorate, she’ll win. Ironically, in this season of Dems running away from Obama, her biggest problem might just be that he isn’t on the ballot. Absent the motivating effect his candidacy has on black voters, Landrieu needs to find other ways to juice black turnout. Signaling to them that she’s aware of the state’s race problems, and that she’s on the right side of that struggle, isn’t an error “politically,” as Halperin suggested. It is a matter of political necessity.