The 1996 Presidential Election in Louisiana, a 12.1% landslide for Nearby Arkansas home state son Bill Clinton over Kansas Senator Bob Dole was the last time that Louisiana would vote Democratic on the presidential level.
Admists a strong economy, and high aprooval Numbers, Clinton Crushed Dole with the rural Cajun Catholic Vote and African American vote—holding Dole to a 24% Margin with White voters overall due to Dole winning over Protestant voters according to this CNN Exit Poll: https://edition.cnn.com/ELECTION/LAPxp.html.