Two weeks after the House narrowly passed a Medicare prescription drug bill despite 19 Republican defections, one of those “no” votes still causes grumbling among GOP leaders — that of Judiciary Chairman Jim Sensenbrenner (R-Wis.).

Bucking the party line is nothing new for Sensenbrenner, who often votes against appropriations bills and other measures that increase spending. But while many conservatives have similar voting records, only the Wisconsin lawmaker wields a full committee gavel, meaning that the leadership sets a higher loyalty bar for him.

“He’s a good chairman, but he made a big mistake with this vote,” said a senior GOP leadership aide, adding that Sensenbrenner’s Medicare stance would be “long-remembered.”

Other aides and senior Republican lawmakers agreed that Sensenbrenner’s vote stood out, especially because the Medicare measure only passed 216-215. What is less clear is whether the Judiciary chairman will suffer any repercussions.

One leadership aide said it was possible that, when his chairmanship comes up for renewal in the 109th Congress, Sensenbrenner could get the same sort of stern lecture that Veterans’ Affairs Chairman Chris Smith (R-N.J.) received during the last Steering process.

Smith has often agitated for Congress to approve more spending for veterans, and at the beginning of the 108th Congress he was warned that, as a chairman, he needed to do a better job toeing the party line.

“On tough votes, we need their help,” a Republican leadership aide said of panel chairmen.

The Medicare bill is only the latest measure on which Sensenbrenner defied his party’s leadership. He has a long history of voting against spending bills, which, depending on the circumstances, may or may not bother Republican leaders.

Those votes definitely anger appropriators, though, especially the handful of times Sensenbrenner has voted against the Commerce, Justice, State and the judiciary bill. That measure funds the agencies overseen by the Judiciary Committee.

He voted against the CJS bill in 2000 and 2001. He voted against several appropriations measures in 2002, including the omnibus spending bill. Last week, he voted against the fiscal 2004 legislative branch measure.

Sensenbrenner spokesman Jeff Lungren said his boss’ actions should not be a surprise to Republican leaders.

“When there is a difference on policy, the chairman lets the leadership know in advance,” he said.

Lungren also argued that his boss has been an extremely productive chairman, moving numerous bills that have drawn support from party leaders.

“In this Congress already, Chairman Sensenbrenner has worked very closely with leadership,” said Lungren, pointing to passage of measures on cloning, medical liability, bankruptcy reform, partial-birth abortion and flag protection, among others.

Indeed, while some lawmakers feel Sensenbrenner can be difficult to deal with, few complain about his performance as chairman; he has drawn particular praise from Majority Leader Tom DeLay (R-Texas). As is the case with some other powerful chairmen, his stubbornness is seen as contributing to his effectiveness.

“Sometimes people complain about his obstinacy, but sometimes that’s what wins the battle for him,” said DeLay spokesman Stuart Roy.

As an example, Roy pointed to the Amber Alert bill. In that case, Sensenbrenner held fast to his strategy of including the creation of a national Amber Alert system in a broader anti-crime bill despite much public pressure from the likes of Ed Smart, father of abducted 15-year-old Elizabeth Smart, to pass a narrower measure similar to the Senate’s version.

In the end, the bill made it into law with many of the House provisions intact.