Republican Jay Dardenne, who ran unsuccessfully for governor, is rebuffing GOP contender David Vitter in the runoff election and backing Democratic candidate John Bel Edwards instead.
Edwards hopes Dardenne's endorsement, announced Thursday, will make Republican voters feel more comfortable with supporting a Democrat in the Nov. 21 runoff.
It comes as polls show Edwards in the lead. Vitter is trying to consolidate Republican support in a conservative state where no Democrats hold statewide office, but his attacks against GOP opponents in the primary have angered some among his own party.
Dardenne, Louisiana's lieutenant governor and a long-time elected official, ran fourth in the primary.
Dardenne described Edwards as someone with integrity who can build coalitions. He said Vitter's campaign was "indicative of someone who is not going to unite Louisiana."