A lot of white Democrats in Louisiana's state legislature switched parties to be treated favorably during last year's redistricting. Many of those who didn't switch lost reelection because of the new districts. Most of the ones who held on did so because they were placed in a majority-black district that will elect a black Democrat whenever the current white incumbent retires.
So I think you could say that they're mostly wiped out in Louisiana, as well.
As far as i know - that's not true. I can remember exatly 2 Democrats defeated in the last legislative elections of 2011 in Louisiana, and both (Jackson in SD-39 and Hardee in HD-44) were black, who lost to another blacks. A couple of white Democrats (Reynolds and Ortego) even won republican-leaning seats in House. According to my preliminary count - of 15 Democrats in state Senate 9 are black and 6 are white (2 of which are relatively conservative whites from black-majority districts, but both serve only second terms, so term limits will not get them until 2019), in House - 23 black and 22 white with 4-5 whites being elected from black-majority districts. So, while percentage of blacks in legislative Democratic caucus will, undoubtely, increase, it's still too early to say that "whites are wiped out" there. After elections of 2015 and, 2019 - may be... A substantial number of "white old guard" will be term-limited then.