BATON ROUGE- As the Louisiana governor's race moves to a runoff, Democrat Rep. John Bel Edwards is trying to build support from GOP voters who didn't choose Republican David Vitter in the primary. Vitter is trying to make his head-to-head matchup with Edwards a partisan competition.

Less than four weeks remain ahead of the Nov. 21 election.

After Edwards' strong primary showing, the Democratic Governors Association is sending staff to Louisiana to help the state representative from Tangipahoa Parish. That suggests national Democrats see Vitter as weakened, after the U.S. senator was attacked by GOP rivals. 

In Saturday's election, Edwards received 40 percent of voter support, compared to Vitter's 23 percent. To turn the tide, Vitter is banking on a campaign strategy that ties Edwards to President Barack Obama, unpopular in Louisiana.