Louisiana's Senate race draws 15 candidates as signup opens

Among the GOP candidates who qualified were U.S. Rep. Charles Boustany, former U.S. Rep. Joseph Cao, U.S. Rep. John Fleming, state Treasurer John Kennedy and New Orleans economic development official Abhay Patel.

Many of the competitors framed themselves as outsiders — even long-time elected officials — seeking to tap into a nation's distrust of the political establishment.

Hebert, a former state senator with no party affiliation, said he would be the only "truly independent candidate" because he refused to take campaign contributions.

Campbell, a state senator for more than 25 years before his election to the PSC, described himself as "not in anybody's shirt pocket" and railed against the "special interests" that he said too heavily influence politics.

The incumbent congressman called on Holden to leave office if he's running for Congress, saying Baton Rouge needs strong leadership in the aftermath of the shooting deaths of three law enforcement officers and an ongoing investigation into the shooting death of a black man by white officers.

Richmond described Holden as "locked in his home" during the massive protests after the shooting of Alton Sterling, a black man killed by white police officers in front of a convenience store where he sold CDs.