This was a vote on an amendment by Jeff Sessions, R-Alabama, to a bill that would reinstate a 120-day limit on how long federal U.S. attorneys may serve when appointed on an interim basis by the U.S. attorney general. Currently, no time limit exists on interim appointments by the attorney general.

According to the underlying bill, the attorney general would be allowed to appoint a U.S. attorney who could serve for no more than 120 days. Then, if a post remains vacant past that period, the chief federal judge in the local district where the vacancy occurred could make further interim appointments. (This was the practice until 2006, when the limit on interim appointments that had previously been in place was removed as part of an anti-terrorism law.)

Democrats sought to reinstate the limits because, in essence, the 2006 law made it so that the attorney general can make interim appointments that can last indefinitely, bypassing the Senate in the process. By law, for these positions to be permanently filled the Senate must sign off on each appointee put forward by the president, but an interim appointment, intended to be temporary, does not have to be submitted for the Senate's approval. Republicans, on the other hand, argue that the system of having a federal judge make an appointment that is traditionally handled by the executive branch is procedurally inappropriate.

The bill itself, and the debate over whether time limits should be placed on how long the attorney general's interim appointees are allowed to serve without Senate confirmation, occurred as part of the uproar over the administration's dismissal of eight U.S. attorneys last year, which raised questions about to what extent those firings were politically motivated.

Sessions amendment would require that district judges making interim U.S. attorney appointments only choose candidates that are either a Justice Department or federal law enforcement official. Candidates under investigation for ethics violations or that have been disciplined for ethics violations would not be allowed to be appointed.

"It will eliminate some examples we have had of judges appointing people who should not have been appointed," said Sessions, himself a former U.S. attorney. "Also, since the prosecution of criminal cases is an executive branch function, the appointment being from the Department of Justice would at least be making it an appointment from the executive branch of the United States."

Patrick Leahy, D-Vermont, said the bill should be passed without amendment, and pointed out that Sessions himself would not have been able to be appointed to the post of U.S. attorney if his amendment were in force at the time. He argued that impartial judges are the best ones for the job, and that the amendment would unduly tie their hands.

"The president should move quickly to appoint the U.S. attorney if there is a vacancy, but in the meantime, the judges are in the best position to appoint somebody. I hope a district court never has to make an appointment. But let's assume you have a case where there is widespread corruption. The judge has to be able to put in someone independent. It worked well for 100 years," Leahy said.

Democrats were able to defeat the amendment 47-50 on a largely party line vote (One Democrat voted yes -- Claire McCaskill of Missouri. Two Republicans voted no -- Chuck Hagel, R-Neb., and Gordon Smith, R-Ore.) Thus, the bill went forward without language that would have required interim U.S. attorney appointments made by federal judges to be picked from Justice Department or law enforcement officials.