BATON ROUGE, La. (AP) — Louisiana congressman Charles Boustany won a fifth term on Saturday by handily defeating his fellow Republican incumbent, Jeff Landry, in a runoff election.

The two men were forced into the same district when Louisiana lost a congressional seat because of anemic population growth in the latest federal census. The state will have six U.S. House seats in the new term that begins in January.

Boustany, a retired doctor from Lafayette, will represent the 3rd District covering southwest Louisiana and Acadiana.

"We're glad to get this done," he said Saturday night. "This looks like a very solid victory. We had a very strong ground game, which was a key element in the runoff. We reached out to a lot of voters with a solid message backed by the results I've gotten in Congress."

With nearly all precincts reporting, Boustany was ahead of Landry by a 3-2 margin. About one-fifth of district voters cast ballots.

The race had been attack-heavy, since both men ran as conservative Republicans opposed to the policies of President Barack Obama and had little philosophical ground in which to distinguish themselves.

The district design favored Boustany, a traditional Republican candidate allied with House Speaker John Boehner. Landry, a freshman congressman, was the tea party favorite, but he was unable to build enough grassroots support to oust Boustany.

Pearson Cross, chairman of the political science department at the University of Louisiana-Lafayette, said Boustany was the "de-facto incumbent" throughout the race.

"Most voters in the district have voted for Charles Boustany, think he's done a good job, are comfortable with him," Cross said.

Landry said it was difficult to overcome Boustany's advantage in the district design. Boustany had represented more than two-thirds of the parishes in the configuration of the new 3rd District.

"In those parishes that I represented, we did extremely well. In those parishes that he represented, he did well. It's kind of tough when seven out of 10 of those parishes were his," Landry said.

Though they had three other challengers in the November election, the two congressmen had campaigned as though it was a two-man race since the election sign-up period in August.

Boustany described his GOP opponent as a good ol' boy politician who would say anything to get elected, habitually skipped votes in Congress and spread distortions about Boustany's record to distract voters from his own lack of accomplishments.

Landry criticized Boustany as lacking the courage to make tough votes for his district and instead following in lockstep with Republican leaders even if south Louisiana voters didn't support the policy.

The race was one of Louisiana's most expensive congressional contests, with nearly $6 million spent between the two men and even more from outside groups. Boustany had a significant edge in fundraising, raising nearly $2 million more than Landry, according to the most recent campaign finance reports filed with the Federal Election Commission.