Yes, Vitter will win, but he is polarizing; unlike Foster and Jindall, because of this, this race LR, not Safe GOP. That's why I quoted Miles.
IMHO, Jindal is even more polarizing. But race is really
at least Likely R. May be the best solution for Democrats in this situation would be not to run their candidate at all and tacitly endorse Dardenne. He could beat Vitter in 1-1 race, and is a pragmatic conservative (probably the best we can expect from Louisiana in statewide race for now). But right now he, most likely, will not get into run-off.