At The Upshot, Nate Cohn provides some empirical data for a reality most of us already understood: the Deep South’s partisan polarization is to an significant extent correlated with race, which in turn has made southern white folks with their characteristic cultural concerns more powerful than ever in the counsels of the GOP.

Some of this data–Cohn’s fascinating map of counties where Democrats won less than 20% of the white vote in 2012–has been, and continues to be, obscured by the decision of the media consortium doing ’12 exit polling not to bother with noncompetitive states, which meant no statewide exits in SC, GA, AL, AR, TN, MS, LA, or TX.

But for the same reason, lumping together southern white voters as uniformly Republican–with the exception of three states, VA, NC and FL, where migrants from outside the region supposedly make all the difference in the world–may oversimplify the picture. According to the 2008 exits, the Democratic percentage of the white vote in the former Confederate States varied significantly, and not just in the three states carried by Obama: FL: 42%; VA: 39%, NC: 35%; TN: 34%; AR: 30%; SC: 26%; TX: 26%; GA: 23%; LA: 14%; MS: 11%; AL: 10%. Were these pretty impressive differences wiped out in 2012? I doubt it.

A state-by-state estimate of the white vote in 2012 done by a diarist at DailyKos (based on backing out heavily pro-Obama nonwhite votes and looking at the remainder) shows an unsurprising uniform slide in the Democratic percentages of white voters throughout the South, but again, big variations persist; SC still shows double the percentage prevailing in MS and LA.

Levels of in-migration from outside the region may have something to do with these variations, but so, too, could urbanization, unionization, the effort exhibited by the Obama campaign, and the strength or weakness of the underlying Democratic organization in this or that state.

It would be helpful if Nate Cohn addressed these variations in a future article for The Upshot. If you’re going to equate white Republican with black Democratic voting levels in an entire region, it’s important to examine places where that is simply not true.

Ed Kilgore

Ed Kilgore is a political columnist for New York and managing editor at the Democratic Strategist website. He was a contributing writer at the Washington Monthly from January 2012 until November 2015, and was the principal contributor to the Political Animal blog.