Rep. Bill Delahunt (D-Mass.), who shares a house with Durbin and Schumer in Washington, said that while “they banter on occasion” over Clinton and Obama, the conversation stays courteous.

“Both of them speak very respectfully of [Clinton and Obama],” he said.

Schumer and Clinton have worked together to steer tens of millions of dollars to constituents in New York, yet Schumer does not hold the same privileged position in her inner circle as Durbin does in Obama’s.

“The relationship between Durbin and Obama is very symbiotic,” said Jimmy Williams, a former senior aide to Durbin who also served a brief stint under Schumer. “These two men have known each other a very long time. They have a lot of the same close advisers and close friends. Each advises the other.”

Williams said that Durbin is already one of the most influential Democrats in Washington but, even so, an Obama victory would enhance his standing significantly.

“If Obama were to become president, that puts Durbin in the catbird seat to be the go-to guy when it came to how a future Obama White House would deal with the Senate, from nominations to a list of other issues,” said Williams.

Less partial observers share that opinion.

“If the perception is that Dick Durbin has a very special relationship with the president I think that would be helpful for Durbin,” said former Sen. Richard Bryan (D-Nev.), who served with both Durbin and Schumer. “Durbin would be considered the go-to guy.

“That would certainly enhance Durbin’s stature,” said Bryan. “That clearly would help Durbin in a race if Reid chose not to run.”

Bryan emphasized, however, that he fully expected Reid to remain majority leader and praised Reid’s ability to share credit with rank-and-file colleagues, a trait Bryan said was essential to serving effectively as Senate leader.

Reid is up for reelection in 2010 and his approval ratings as measured by the Las Vegas Review Journal range between the low 30s and low 40s — not significantly better than President Bush’s.  

Reid spokesman Rodell Mollineau said that Reid would run for reelection and that he planned to serve as majority leader “far into the future.”

Some Senate insiders, however, have questioned how much impact Obama as party nominee or president would have on Durbin’s prospects of becoming majority leader.

“I don’t think it would have any impact,” said Sen. Byron Dorgan (N.D.), chairman of the Senate Democratic Policy Committee. “The Senate fiercely guards its own decision-making. I don’t think the structure or leadership of the Senate has very much to do with the presidency.”

Dorgan said that many senators disapproved of the role Bush played in installing former Sen. Bill Frist (R-Tenn.) as majority leader when the post opened unexpectedly.

“That happened once with Bill Frist and it wasn’t particularly well-received and didn’t work out very well,” said Dorgan.

Don Ritchie, the associate Senate historian, said Durbin might end up spending much of his time on the chamber floor defending Obama from attacks. Ritchie noted that former Arkansas Sens. Dale Bumpers (D) and David Pryor (D) devoted themselves to defending former-President Bill Clinton when his administration faced political assault.