New Orleans ? Republicans picked up a congressional seat in southern Louisiana on Saturday, but gave another right back to Democrats in a second, much closer runoff election that also was in Cajun country.

A longtime Democratic bastion in Louisiana’s 7th District went to Republican Charles Boustany, a retired heart surgeon. With 94 percent of the precincts reporting, Boustany had 72,223 votes or 55 percent, and Democratic state Sen. Willie Landry Mount had 58,968 or 45 percent.

Farther south, Billy Tauzin III narrowly lost a close race to replace his retiring father, a Republican House of Representatives powerhouse. In the 3rd District, with 100 percent of precincts reporting, Democrat Charles Melancon had 57,609 votes, and Tauzin trailed him by barely 500 votes, with 57,092.

The last bits of unfinished business from the 2004 congressional election season, both races were marked by heavy negative campaigning and light voter interest.

The runoffs were necessary because none of the candidates won a 50 percent majority. Although the seats can’t change control of the House, Republicans hoped to pad their majority, while Democrats were trying to beat back GOP momentum from Election Day.

Vice President Dick Cheney and Democratic Gov. Kathleen Blanco tried to drum up enthusiasm for their candidates, but parish officials said turnout was running extremely low with voters apparently turned off by a relentless barrage of attack ads.

In the 3rd District along Louisiana’s swampy southern coast, Melancon, a former state representative, has derided his 31-year-old opponent as a callow fraternity boy who is trying to inherit the seat from his 12-term incumbent father, Rep. Billy Tauzin Sr.

Tauzin has returned fire, calling Melancon a liberal who has voted in favor of sex-education for small children.

Republicans have poured money into the other Cajun country race, where Boustany has portrayed Mount, a state senator, as a tax-happy liberal. Mount, in turn, has accused Boustany of favoring tax cuts for the rich and not caring enough about reforming health care.

Both candidates are trying to fill the seat being vacated by Democratic Rep. Chris John, who ran unsuccessfully for the U.S. Senate this year.