WASHINGTON (CNN) -- The National Republican Campaign Committee is using some its scarce resources to target one of the most senior Democrats in the House: Rep. John Murtha, D-Pennsylvania.
A campaign commercial released Tuesday uses video clips of Murtha's recent comments calling his western Pennsylvania district "a racist area" and "redneck."
The ad was released to reporters Tuesday and is slated to begin airing Thursday in the Pittsburgh television market, the committee announced.
The ad also uses includes a clip from a news conference where Murtha talked about civilians killed in Haditha, Iraq, in 2005, saying U.S. Marines "killed innocent civilians in cold blood." The ad ends by saying, "Enough."
"John Murtha has called American soldiers cold-blooded killers and the voters of his district racists and rednecks," committee spokesman Ken Spain said. "By doing so, he has besmirched the reputation of the voters he claims to represent and turned himself into a national embarrassment in the process."
Under campaign finance law, the committee is allowed to contribute up to $84,000 in "coordinated funds" to an individual campaign. Murtha's challenger is William Russell, a Iraq war veteran who authorized the ad.
Murtha's campaign dismissed the ad Tuesday.
"If Republican William Russell wants to accept help from George Bush, that's his choice," Murtha spokesman Matt Mazonkey said. "We choose to talk about the issues that matter in this campaign, and I think the voters know the difference between a mouthpiece of the Bush administration and Mr. Murtha, who is fighting hard for the people of western Pennsylvania."
On the flip side, the Democratic Congressional Campaign Committee says it has paid for an ad criticizing Russell that is slated to run this week.
In an interview October 15 with the Pittsburgh Post Gazette, Murtha, who endorsed Sen. Hillary Clinton for president in March, predicted that Sen. Barack Obama would win the state of Pennsylvania but said that there was some hesitancy among voters.
The paper posted video of the interview on its Web site, with Murtha saying, "There's no question western Pennsylvania is a racist area."
Murtha apologized the next day, saying, "I apologize for making the comment that 'western Pennsylvania is a racist area.' While we cannot deny that race is a factor in this election, I believe we've been able to look beyond race these past few months and that voters today are concerned with the policy differences of our two candidates and their vision for the future of our great country.
"Sen. Obama has shown sound judgment and has presented us with a change from the failed policies of George Bush and John McCain. I believe he will win both Pennsylvania and the White House," he added.
But Republicans seized on the remarks.
Days later in an interview with a local television station, Murtha said his district was "really redneck" years ago.
Last weekend's episode of NBC's "Saturday Night Live" included a spoof of Murtha's remarks about his constituents in a skit about a visit by Democratic vice presidential candidate Joe Biden to Pennsylvania.
A poll by Susquehanna University released Thursday showed the race tightening, with Murtha ahead of Russell by just 4 points. Republicans feel that they have an opportunity in an otherwise bleak environment to challenge the high-profile Democrat.
CNN political producer Ed Hornick contributed to this report.