WASHINGTON -- As the Senate this month neared its summer recess, the senior Republican senator delivered a rebuke to the second-ranking Democratic leader. It generated little public notice, but the incident reflected that the current Senate as a partisan snakepit follows some traditional folkways.

Sen. Ted Stevens of Alaska, Senate president pro tempore, thwarted Senate Democratic Whip Richard Durbin of Illinois, who was seeking a $2 million earmark for the University of Chicago. Stevens, as a reigning king of pork, cracking down on earmarking is drenched in irony. Durbin's earmark was rejected on a party-line vote, after debate that got personal on Stevens's part.

Why this violation of senatorial politesse? Public mortification of an opposition leader reflects harshness on today's Capitol Hill. It also points up pitfalls of Durbin's pugnacious style that elevated him to No. 2 Democrat after eight years in the Senate. Tough, old Ted Stevens was mad and determined to get even after humiliation by Durbin last autumn.

On Nov. 16, 2005, Durbin took the Senate floor to attack Stevens for permitting oil company executives to lie to the Senate Commerce Committee by not putting them under oath. Two days short of his 82nd birthday, Stevens was outraged by this assault on his integrity. Durbin's remarks about the man fourth in line for the U.S. presidency indeed were extraordinary.

Displaying a famous temper often seen during 37 Senate years, Stevens roared onto the floor after Durbin's speech. He demanded Durbin's apology under Senate Rule 19 prohibiting senators from accusing each other of "unworthy" behavior. The Senate parliamentarian said the rule did not apply because Stevens was not on the floor objecting when Durbin spoke. Durbin, who gives no quarter, declined to apologize. He had made a formidable enemy, but Stevens bided his time.

Payback time came Aug. 2, when the Defense appropriations bill was debated under management of Stevens as Appropriations subcommittee chairman. Durbin proposed his University of Chicago earmark to improve imaging of traumatic brain injuries. The hook connecting this with Defense was "adaptation of current technologies to treat brain injuries suffered in combat." Durbin had been turned down in Stevens's subcommittee, but he used his access as whip to try again on the floor. The co-sponsor -- Durbin's junior Senate colleague from Illinois, Barack Obama -- was nowhere to be seen for what ensued.

Stevens was prepared. "We have to stop using Defense money for contracts with universities and basic research at the suggestion of a single senator," he said. "Not one" official from the military community, he said, "came to us and said we needed more money for brain research." Similar lack of support in the executive branch breeds earmarks, which have reached epidemic proportions.

"I plead guilty," responded Durbin. "It is an earmark." He said he and Obama were taking money out of their earmarks to finance this expenditure. Characteristically, he played on heartstrings about 1,700 wounded soldiers returning from combat with brain damage: "Would we want to at least err on the side of these soldiers?"

That was enough for Stevens to tell more about dealings with a Senate colleague than is usually revealed: "We had a total of $3 billion in requests from this subcommittee for medical research from other senators. We turned them all down. The senator from Illinois wouldn't take 'no'." Warming to his subject, Stevens went on: "We cannot do this just for one senator, and I have been a whip, and I understand what it means to have access to the floor and make a demand."

Durbin's amendment lost, 52 to 43. Stevens collected all Republican senators except Conrad Burns of Montana and Mike DeWine of Ohio, both facing uphill battles for re-election. The only Democrats opposing Durbin were Daniel Inouye of Hawaii (Stevens's subcommittee co-chairman) and reformer Russell Feingold of Wisconsin.

Stevens's Defense bill, awaiting final action when Congress reconvenes, included $5 million for the Dwight D. Eisenhower Memorial Commission and $500,000 for a traveling exhibit on World War II. Rejecting Durbin's earmark did not signify the coming of reform in the Senate, but looked more like Stevens and other Republicans getting even with the senator they like least.