The 2004 United States Senate election in Louisiana was held on November 2, 2004. Incumbent Democratic U.S. Senator John Breaux decided to retire. Republican U.S. Representative David Vitter won the jungle primary with 51% of the vote and avoided a runoff.
During the campaign, Vitter was accused by a member of the Louisiana Republican State Central Committee of having had a lengthy affair with a prostitute in New Orleans. Vitter responded that the allegation was "absolutely and completely untrue" and that it was "just crass Louisiana politics."
Vitter won the Louisiana senatorial jungle primary with 51.0 percent of the vote. The field of opponents including two major Democrats, then Seventh Congressional District Congressman Christopher John, who got 29.4 percent of the vote, and state Treasurer John Neely Kennedy (no relation to the Massachusetts Kennedys), who got 15.1 percent.
Vitter won at least a plurality in 56 of Louisiana's 64 parishes. John carried nine parishes, all but two of which (Iberville and Orleans) are part of the House district he represented.
Kennedy changed parties and ran as Republican in 2008 against Louisiana's senior senator, Democrat Mary Landrieu. Landrieu won her third term in that election.