Turnout was brisk across the state.
In the presidential race, Romney's success in Louisiana had been so expected that neither the former Massachusetts governor nor President Barack Obama did much campaigning in the state in advance of the election, focusing on battleground states.
Romney received 59 percent of the vote in Louisiana with nearly all precincts reported.
The outcome of most of the state's U.S. House races seemed to have been decided in August, when few well-financed challengers signed up to oppose incumbent congressmen.
But at least one of the state's GOP members of Congress won't return in January.
Boustany and Landry were fighting for the 3rd District seat covering southwest Louisiana and Acadiana in a bitter battle laden with attack ads and accusations of lies and dirty tactics.
The two congressmen tried to stake out much the same philosophical territory, both running as conservatives, leaving them to distinguish themselves largely by slamming each other. Landry was running as the tea party favorite, while Boustany was considered a more traditional Republican candidate.
Louisiana's other Republican congressmen had little organized competition:
—Alexander, the dean of Louisiana's U.S. House delegation and a contractor, was first elected to Congress in 2002. He'll be entering his sixth term representing the 5th District, which includes Monroe and Alexandria.
—Scalise, a former state lawmaker, will be entering his third full term in the 1st District that covers suburban New Orleans and coastal southeast Louisiana.
—Fleming, a doctor and owner of Subway and UPS stores, also will be taking a third term in the northwest Louisiana-based 4th District.
—Cassidy, a doctor and former state senator, was first elected to the Baton Rouge-based 6th District seat in 2008. He's considered to be a likely opponent for Democratic U.S. Sen. Mary Landrieu when she runs for re-election in 2014.