U.S. District Judge Charles Kornmann of Aberdeen has taken senior status, meaning he will continue hearing cases but pare down his workload.

His decision to step down as a full-time judge opens the door for the president to replace Kornmann, but it's considered unlikely that will happen during the final few months of a Bush presidency.

Judges on senior status earn full pay and raises by working a quarter of their previous caseload.

Federal district judges are paid $169,300 a year.

Kornmann, one of three federal judges in South Dakota, presides over the central and northern sections of the state, typically hearing federal court cases in Pierre and Aberdeen.

The state's other federal judges are Lawrence Piersol in Sioux Falls and Karen Schreier in Rapid City.

All three were appointed to the bench in the 19990s by Democratic President Bill Clinton.

Kornmann could have reduced his caseload and become a senior judge in fall 2007, but he stayed on full-time after Judges Schreier and Piersol took on about two-thirds of the criminal cases in Pierre.

In theory, Republican Sen. John Thune would recommend a replacement for Kornmann to President Bush. Bush would nominate a successor and the U.S. Senate would confirm.

But that appears unlikely. Congress is in recess until September, and the Democratic-controlled Senate has no incentive to confirm Bush's judicial nominees ahead of an election in which Democrats could win the presidency and solidify their hold in the Senate.

Karen Redmond, a spokeswoman for the Administrative Office of the U.S. Courts, said it's unlikely there's enough time for a confirmation before this Congress ends.

"You have a vacancy, and you probably will have one for a while," she said.

Thune spokesman Kyle Downey said: "Our office has not received any notification from Judge Kornmann of his decision, so starting the process at this late date may effectively prevent this vacancy from being filled this year."

As of Tuesday, there were 41 vacant federal judgeships. Of those, 33 nominees await Senate confirmation. Any nominee not confirmed by the time Congress adjourns this year would have to be nominated again by Bush's successor.