WASHINGTON (CNN) -- Sen. Dick Durbin, D-Illinois, is giving up his chairmanship of the Crime and Drugs Subcommittee and giving it to Sen. Arlen Specter, D-Pennsylvania, Durbin spokesman Joe Shoemaker said Thursday.
Sen. Arlen Specter announced Tuesday he is switching to the Democratic Party.
Durbin, the second-ranking Democrat in the Senate, agreed to give up the post after a day of intense negotiations and public feuding between Specter and Senate Majority Leader Harry Reid over Democrats' stripping Specter of his seniority on key committees.
The subcommittee is a relatively powerful position in that it apparently oversees about 60 percent of the Department of Justice, according to Shoemaker.
A Democratic leadership source, who did not want to speak on the record about internal Democratic dynamics, also told CNN that Democrats decided to do this for Specter for two main reasons.
First, they want Specter to win re-election, and this gives him a powerful legislative perch from which to run. Second, the Senate Judiciary Committee is about to deal with a new Supreme Court nomination.
"The last thing we want is a disgruntled Democrat at the end of the dais," this Democratic source told CNN.
The full Senate voted Tuesday to strip Specter of his seniority, dropping him to the bottom of the pile on every committee he sits on. The action came on a resolution -- passed on a unanimous voice vote -- that set out committee assignments for the entire Senate. Specter suggested other Democratic senators had objected to him moving ahead of them in the all-important seniority ranks.
Specter said Reid had told him "I would maintain my committee assignments and that my seniority would be established as if I'd been elected in 1980 as a Democrat."
After the vote, Specter said, "The caucus has some concerns, some people who would be passed over, and we're going to work it out," he said. "... I'm confident that Sen. Reid's assurances on my seniority will be fulfilled."
Specter jumped from the Republican Party to the Democratic Party last week, putting the Democrats within reach of a 60-seat "supermajority" that could make it all but impossible for Republicans to block Democratic legislation.
But there has been complaining among Democrats about Specter leapfrogging long term Democrats in seniority and also about Specter's loyalty to the party.
Sen. Debbie Stabenow, D-Michigan, suggested Specter had irritated his new colleagues by telling the New York Times the Minnesota courts should "do justice" by declaring Republican Norm Coleman the winner of a bitterly disputed Senate race against Democrat Al Franken.
"I think it made many members very upset," Stabenow said in answer to a CNN question about whether Specter would have maintained his seniority if he had not made the comment. "... It was definitely something that concerned everybody. Yeah."
Sen. Barbara Mikulski, a D-Maryland, phrased the concerns of the caucus more generally.
"We have people here who have worked very hard to achieve their seniority on their committees and subcommittees, and we should keep the same leadership we've had," she told CNN. "It's not personal to Senator Specter."
Reid's spokesman Jim Manley, asked to reconcile the grumbling with the move to give Specter a subcommittee chairmanship, said, "Senator Reid has heard the grumbling. Senator Specter has a year-and-a-half to prove himself as a Democrat."
CNN's Ted Barrett contributed to this report.