Primaries in Louisiana today teed up what have the potential to be heated general-election matches.

Sen. David Vitter defeated latecomer Chet Traylor, a retired state Supreme Court justice, in the Republican primary. Vitter had 88 percent to Traylor’s 7 percent with 88 percent of precincts reporting. A poor showing would have revealed his weakness in the general election. Then Vitter will face Rep. Charlie Melancon (D). The Democrat was winning his own primary over two other candidates with 68 percent of the vote as 88 percent of precincts finished reporting.

Partially because of Vitter’s personal troubles over the past few years, the general election race is likely to be more competitive than the Democratic and Republican primaries were. In 2008 the Senator admitted having hired a prostitute in Washington, D.C. Nonetheless, he leads Melancon in early polling by double digits.

In the Republican primary for Melancon’s 3rd district seat, lawyer Jeff Landry upset former Louisiana Speaker Hunt Downer. With 99 percent of the precincts reporting, Landry had nearly 50 percent to Downer’s 36 percent. Engineer Kristian Magar had 14 percent. Since no one crossed the 50-percent threshold, Landry and Downer will continue on to a runoff on Oct. 2.

In the second district, state Rep. Cedric Richmond held off three opponents in the Democratic primary. With 34 percent of precincts reporting, he had 64 percent of the vote. Richmond will face Rep. Anh “Joseph” Cao, widely believed to be the most endangered Republican incumbent in the nation. Cao defeated indicted Rep. William Jefferson (D) in a 2008 runoff following Jefferson’s ethical problems.

Richmond earned the support of a number of Democrats and Democratic groups in the weeks leading up to the primary, including the Democratic Congressional Campaign Committee, Sen. Mary Landrieu and New Orleans Mayor Mitch Landrieu. He defeated state Rep. Juan LaFonta, former Jefferson chief of staff Eugene Green and activist Gary Johnson.

Republican Reps. Steve Scalise, John Fleming and Bill Cassidy were unopposed in their primaries, and Rep. Rodney Alexander (R) defeated marginal opposition. All four are expected to cruise to victory in November.

Rep. Charles Boustany (R) was unopposed in his primary, and no Democrats filed in his district.