One of the Republican challengers Louisiana Sen. David VitterDavid Bruce VitterLouisiana Republicans score big legislative wins Trump calls on Republicans to vote out Democratic Louisiana governor amid GOP infighting Grocery group hires new top lobbyist MORE defeated in the gubernatorial primary has chosen to endorse Vitter’s Democratic challenger instead of falling in line with the GOP after a vicious primary fight.

“I will remain a Republican, but I also am someone who believes in voting for the person, not the party,” Lt. Gov. Jay Dardenne said during a press conference Thursday morning, according to video from WDSU News.

“How could I pretend that everything I said about David Vitter less than two weeks ago has no meaning? When are we as Louisianans going to stop tolerating the embarrassment that too many of our elected officials have heaped upon this state?”

Vitter will face off against state Rep. John Bel Edwards in a Nov. 21 general election after the pair were the top two vote-getters in the state’s “jungle" primary, which pits all candidates against each other regardless of party.

That primary turned ugly when Vitter’s Republican rivals jumped on accusations that he fathered a child with a prostitute and used a private investigator to spy on political opponents. Dardenne called Vitter a “stain on Louisiana” days before the primary. 

Vitter and his allies responded with attacks of their own against Dardenne and businessman Scott Angelle’s conservative chops.

The GOP has a registration advantage, but political experts from the Bayou State told The Hill last month that the race will boil down to whether Vitter can pull together the party after such a contentious primary.

Edwards holds a 16-point lead over Vitter in a new Market Research Insight poll provided to The Advocate, a Baton Rouge newspaper.