Coburn slams negative attacks
© Greg Nash

Sen. Tom CoburnTom CoburnFormer GOP senator: Trump has a personality disorder Lobbying World -trillion debt puts US fiscal house on very shaky ground MORE (R-Okla.) waded into the race to replace him on Thursday, decrying negative attacks from groups backing T.W. Shannon and heaping praise on Rep. James LankfordJames Paul LankfordFox News host on Moore: 'I would kick his head in if it was one of my daughters' Protecting free speech rights through tax reform Senate GOP moves forward on taxes MORE (R-Okla.).

Outside groups have poured over $1 million into the race, largely on ads in support of both candidates. But last week, one pro-Shannon group launched a negative attack on Lankford, and another followed suit Thursday. Shannon himself ran an ad that contrasted their records, declaring that Lankford is “going Washington’s way.”

Coburn said the outside attack ads, which charge that Lankford “votes with liberals” and is a “Washington insider,” “crossed an important line.”

"The current political advertisements by groups such as Senate Conservatives Fund and Oklahomans for a Conservative Future supporting T.W. Shannon have crossed an important line — they simply aren't truthful and they mischaracterize James Lankford's service in Congress,” Coburn said in a statement.

Coburn also praised Lankford as “a man of absolute integrity.”

“We haven't always agreed, but he is one of the most honest, thoughtful and sincere men I have met in my time in Washington,” Coburn added. 

And he went on to refute some of the conservative attacks, emphasizing his experience outside Washington and his willingness to fight the “status quo.”

“[Lankford] has life experience and a perspective outside the career political bubble by which to make good decisions. He has fought an often lonely battle against the status quo and has dedicated himself to the hard work of oversight of federal agencies,” Coburn said.

While Coburn’s statement wasn’t an outright endorsement, it’s certain to give Lankford a considerable boost in the Oklahoma GOP primary, where all three candidates are looking to frame themselves as the heir to Coburn’s conservative legacy in the Senate. A poll out Wednesday from a pro-Shannon group showed a tight race, with Shannon down by 2 points against Lankford, but that was a considerable drop-off in support from the group's last survey, conducted in April.

Coburn went so far as to imply the negative attacks from pro-Shannon groups raise questions about Shannon’s ability to govern.

“As a voter, I believe the conduct of a campaign is a critical test of how a man or woman values this great trust. How someone runs a campaign says a lot about how that person would govern,” he says.