Coburn, speaking to a scrum of reporters Monday evening, dismissed the letter — spearheaded by Sen. Jim DeMint (R., S.C.) — as “aspirational” and “meaningless.”

“I’m out there pretty bold on what I believe in terms of what we ought to tackle,” Coburn said. “And I’m willing to take some tax increases.”

And he’s not merely referring to higher “revenue,” which many Republicans have signaled a willingness to accept.

“If we could have our way, that’s what we’d get but we’re not going to get our way, are we?” Coburn said. “We’re not undermining any of the positions I’ve said. We’re going to have to have revenue increases to get entitlement reform. I stand firm to it.”