CQ Politics forecasted the race as "Safe Democrat" for 9-term incumbent William Jefferson, but the Republican narrowly defeated him in an upset.

[5] On July 30, 2005, Jefferson was videotaped by the FBI receiving $100,000 worth of $100 bills in a leather briefcase at the Ritz-Carlton hotel in Arlington, Virginia.

This is "believed to be the first-ever FBI raid on a Congressional office,"[9] raising concerns that it could "set a dangerous precedent that could be used by future administrations to intimidate or harass a supposedly coequal branch of the government.

Jefferson faced six African-American challengers along with newscaster Helena Moreno in the first primary, all of them clamoring for change from Louisiana's reputation for political corruption.

[14] On November 30 the New Orleans Times-Picayune editorially endorsed Cao[15] while on the op-ed page its columnist James Gill asserted that Jefferson's reelection "is not going to happen.

[17] Cao's candidacy received the endorsement of the Alliance for Good Government,[18] the Family Research Council's Action PAC,[19] Louisiana Governor Bobby Jindal,[20] and even entertainer Pat Boone.

The New Orleans Gambit Weekly, citing its opposition to Jefferson's alleged corruption and Cao's noncommittal statements on embryonic stem-cell research, made no endorsement.

[25] Final unofficial results on the Louisiana Secretary of State's web site showed Cao with 33,122 (49.55%), Jefferson 31,296 (46.82%), Kahn 548 (0.82%), and Rahim 1,880 (2.81%).

Fleming, a former Webster Parish coroner and a businessman defeated trucking company executive Chris Gorman in the Republican runoff primary held on November 4.

Republican State Senator Bill Cassidy defeated Democratic incumbent Don Cazayoux in the November 4 election by a margin of 48% to 40%.

State Representative Michael L. Jackson, who had run against Cazayoux in the Democratic primary in the special election, ran as an independent with funding from long-time Cassidy supporter Lane Grigsby.

[30] Cazayoux was one of five incumbent House Democrats to be defeated in the 2008 congressional elections, along with Nancy Boyda (D-KS), William J. Jefferson (D-LA), Nick Lampson (D-TX), and Tim Mahoney (D-FL).

Republican incumbent Charles Boustany defeated Democratic State Senator Don Cravins, Jr. and Constitution Party candidate Peter Vidrine by a solid margin in this district based in southwestern Louisiana.