The GOP is continuing its campaign to paint longtime West Virginia Sen. Robert Byrd (D) as vulnerable if he seeks re-election next year — and boost its efforts to recruit a top challenger into the race.

The National Republican Senatorial Committee on Friday released a new poll that showed the veteran lawmaker just barely above the 50 percent mark.

The survey, conducted by the Anderson Group for the NRSC, showed Byrd leading Rep. Shelley Moore Capito (R) 52 percent to 42 percent in a hypothetical head-to-head matchup.

Capito, the only Republican in the state’s Congressional delegation, is being wooed by national and state party leaders to challenge Byrd in 2006. In response to the poll, the Congresswoman said she was flattered by the encouragement she has gotten but remains focused on her current job — for now at least.

“I intend to keep my options open for 2006 and make a decision in the coming months,” Capito said in the statement.

NRSC spokesman Brian Nick said the poll is encouraging news for Capito, and he argued that the results help refute the belief that Byrd, long considered an institution in the state he has represented in Congress for more than 50 years, is invincible at the ballot box.

Since the beginning of the year, Republicans have launched an aggressive effort to paint Byrd as out of touch with mainstream voters in a state that has trended Republican in national elections. Byrd, who will turn 88 in November, has taken a high-profile role in the ongoing battle over judicial nominees and the so-called “nuclear option,” and he has also been a vocal critic of the Bush administration’s foreign policy.

The former Appropriations chairman has never experienced a competitive challenge since being elected to the Senate in 1958. He has won re-election with more than 60 percent of the vote since.

Nick said that while Byrd is a known commodity to voters, Capito, who is far less recognized, still has room to grow her support.

“There’s nowhere to go for him but down,” Nick said. “Our sense is that that 52 percent is as soft as it is because a lot of people haven’t been introduced to Congresswoman Capito at this point, or another challenger.”

The NRSC did not release any other findings from the poll. Other than Capito, who is the daughter of a former West Virginia governor, there have been no other top-tier Republican floated as a possible opponent to Byrd.

Democratic Senatorial Campaign Committee spokesman Phil Singer scoffed at the notion the GOP poll numbers reflect Byrd’s vulnerability.

“It’s a little surprising to see the Republicans crowing about a poll that has their choice candidate losing by double digits,” Singer said. “All of the pundits that hail the Republicans’ political savvy might want to rethink that. Last time I checked losing by double digits was nothing to crow about.”

The poll of 500 likely voters was conducted March 15-16 and had a 4 percent margin of error.