re: Can you guys explain to me (a Mississippian) how Louisiana has a Democratic Gov?

I'll throw my two cents in:

1. LA isn't as conservative as you might think. It is very socially and culturally conservative (christian, anti-abortion, pro gun, patriotic) but honestly not very fiscally conservative. That's partially because we are a poor state and the legacy of the Longs.

2. Under Jindal, taxes got cut quite a bit (I used passive voice for reason). Plus post-katrina money went away and oil prices dropped. Rather than rebalance the budget (or god forbid, undo the tax cuts) he did some cutting and implemented a lot of efficiencies, but he mostly used a lot of gimmicks. That plus looking like he cared more about president than governor made him relatively unpopular.

3. JBE was best suited to capitalize on 1 and 2. He was the democratic floor leader under Jindal so his "anti-Jindal credentials were impeccable. Vitter wasn't exactly pro-Jindal, but it wasn't as clear. JBE also fit the social conservative but not fiscally conservative mold with his west point/honor code/pro-gun/pro life image. At least compared to scandal ridden Vitter. Several liberal reporters disingenuously played up the "I can't even tell he is a democrat!" angle.

4. Lastly, Vitter is a jerk (allegedly). He went after the two over republicans (Dardenne and Angele) harshly enough that Angele refused to support Vitter and Dardenne actually endorsed JBE. Vitter's logic was "I want to get in a run-off with the democrat I can beat so I will attack the other republicans." Made sense at the time. But you add on the Vitter supposedly rubbed people the wrong way on an interpersonal level and you get republicans abandoning Vitter.

tldr version:
Unpopular Jindal
West point honor code
hookers