here's the Attorney General Map, Caldwell in red, Foti in green
That is a weird set of results.
It's not that weird. Alexander did well in the Republican strongholds of the state - Northern LA, Lafayette and St. Tammany. It seems that Foti held onto the Cajun (south central LA) strongholds and Caldwell picked up most of the rest.
That's the basic picture, yeah. What caught my eye was the eastern end of Acadia - Terrebonne, Lafourche, Plaquemines - voting for Caldwell, that weird little patch of three Caldwell parishes around Natchitoches, and the more heavily black areas around Baton Rouge voting for Foti (while both New Orleans and NE Louisiana voted for Caldwell). However, the first is probably explained by proximity to New Orleans (and perhaps media markets as well?) and in the last case, I somewhat overestimated the blackness of places like Saint James and St John the Baptist and underestimated their frenchness.
Louisiana Parishes with above-average Cajun populations:*
Acadia Parish 38.0
Allen Parish 19.8
Ascension Parish 29.7
Assumption Parish 36.8
Avoyelles Parish 31.5
Calcasieu Parish 24.3
Cameron Parish 44.5
Evengeline Parish 34.2
Iberia Parish 32.2
Iberville Parish 21.1
Jefferson Parish 19.6
Jefferson Davis Parish 38.0
Lafayette Parish 29.7
Lafourche Parish 42.6
Livingston Parish 18.7
Plaquemines Parish 23.3
Pointe Coupee Parish 30.0
Saint Bernard Parish 24.1
Saint Charles Parish 26.1
Saint James Parish 25.0
Saint John the Baptist Parish 19.4
Saint Landry Parish 26.5
Saint Martin Parish 35.8
Saint Mary Parish 27.9
Saint Tammany Parish 18.2
Terrebonne Parish 35.0
Vermilion Parish 41.5
West Baton Rouge Parish 26.1
Louisiana Parishes with above average black populations**
Bienville Parish 43.8
Caddo Parish 44.6
Claiborne Parish 47.4
Concordia Parish 37.7
De Soto Parish 42.2
East Baton Rouge Parish 40.1
East Carroll Parish 67.3
East Feliciana Parish 47.1
Iberville Parish 49.7
Lincoln Parish 39.8
Madison Parish 60.3
Morehouse Parish 43.4
Natchitoches Parish 38.4
Orleans Parish 67.3
Ouachita Parish 33.6
Pointe Coupee Parish 37.8
Red River Parish 40.9
Richland Parish 38.0
St. Helena Parish 52.4
St. James Parish 49.4
St. John the Baptist Parish 44.8
St. Landry Parish 42.1
Tensas Parish 55.4
Webster Parish 32.8
West Baton Rouge Parish 35.5
West Feliciana Parish 48.6
*"Acadian/Cajun", "French" and "French Canadian". Percentage of total ancestries tallied, from 2000 census sample. State average 17.5%
**Black only, from 2000 census. State average 32.5%