A typical bill moving through the Senate has a number of institutional hurdles to clear: subcommittee, committee, leadership and Coburn. It’s that last one that you won’t find in a textbook.

Tom Coburn, an Oklahoma Republican, has long been known as the Senate’s gadfly, crusading against wasteful government spending. In the last year, however, this gadfly has gone through a metamorphosis and is now more of a scorpion: If you’re not careful, he’ll kill your bill.

Story Continued Below

For that reason, Senate aides on both sides of the aisle now take legislation directly to Coburn’s office before moving forward to make sure he has no objections — whether he’s on the relevant committee or not. If he does, they often swallow their pride and make the changes he’s asking for.

Republican leadership has learned to live with this new element of the Senate process. “He’s definitely been a fly in the soup. I can think of another apt analogy, but that’s the one I’ll use,” said Sen. John Cornyn (R-Texas), the fifth-ranking Republican. “I think at different times it’s been irritating but, I think, in a very positive sort of way, because it has forced us to refocus on spending as a core issue and one that unifies — or at least used to unify — Republicans.”

Whether they’re for items big — say, breast cancer research — or small, such as the naming of a post office, Coburn is open about his holds and the principle(s) behind them. “I’m not trying to block legislation. I’m trying to make it better. But we have some parameters,” he said. “People are recognizing that we’re not hard to deal with if you talk with us, but if you won’t talk with us, we are hard to deal with.”

Cornyn said that Coburn’s rising influence comes from his years of consistency. “He’ll take a shot at any piece of legislation, whether it’s Democratic or Republican, if he feels like it deserves it,” he said. “I think there is a sense he wasn’t going away, so we’ll have to deal with him.”

Sen. Olympia Snowe (R-Maine), after pausing to speak cautiously, agreed: “I’ve found that, if you approach him and deal with him, he’s easy to work with.”

Easy, though, is relative. “I think he’s open about the issues, but he is pretty persistent. It’s not easy,” said Sen. Ben Cardin (D-Md.). “It’s been tough. We’ve had some success. Some amendments we’ve gotten through.”

Coburn has a hold on several of Cardin’s bills, and he recently put one on small-business legislation backed by Snowe. Both are hoping to work out their differences with Coburn.

They’ll have to get in line. Although the Senate doesn’t keep official records on how many holds senators employ, Coburn’s office does: He’s holding 95 different pieces of legislation for a variety of reasons. His jam-fest likely ranks as one of the most prolific in the history of the institution, said Donald Ritchie, an associate Senate historian.

If senators thought there might be a holiday reprieve in their efforts to get crucial spending measures passed, Coburn let them know otherwise in a letter last week. “In the remaining hours of this session of Congress,” he promised, “I will not agree to any unanimous consent requests to authorize or appropriate increased spending or expand the size and cost of the federal government.”

Coburn has the rules of the Senate in his favor. “It’s difficult to work around a senator. Ultimately, it’s a cloture vote. It’s very time-consuming, and you can’t do that on most issues,” said Cardin.

Coburn’s liberal use of the senatorial privilege is what gives him his sting. It has earned him increased influence, won him some battles and helped him acquire some unlikely allies, such as Sen. Barack Obama (D-Ill.) — but it’s also brought out a fair share of detractors.

Jim Manley, a spokesman for Senate Majority Leader Harry Reid (D-Nev.), is no fan, saying in an e-mail that Coburn is “exercising his rights as a senator, but his approach is contrary to the traditions of collegiality and bipartisan compromise in the Senate. No wonder it’s so hard to get things done when a handful of junior members insist on a their-way-or-the-highway approach to legislating.”

Sen. Dianne Feinstein (D-Calif.), as chairwoman of an appropriations subcommittee, must get spending bills past Coburn. His tactics have exasperated her to the point where she has developed a new way to define what he does. “I think it’s a way an individual tries to exacerbate their power, and it’s really unfortunate,” she said, her voice rising.