Rivalry or not, the Senate is big enough for Joe Lieberman and Ned Lamont.
Congress returns for business Tuesday, and Lieberman, the Democrat now running as an independent, will be back for committee assignments, defense legislation and perhaps party meetings.
Close by will be Lamont, who upset Lieberman in the Aug. 8 primary, seizing the Democratic nomination for the Connecticut seat. Lamont plans to meet Wednesday with party leaders, union leaders and business groups.
"I'm not spending much time in Washington, but I think it's important I at least get introduced down there," Lamont said. "A lot of people down there have a certain interest in this race so I figured some of them are saying stuff about me and I might as well meet them."
Lamont will skip the traditional Tuesday luncheon for senators, an event that sometimes attracts candidates, and avoid a likely encounter with Lieberman.
"I'm always happy to cross paths," Lamont said. "I'm not doing anything to avoid any of that."
The three-term senator is bucking his party after a bitter primary loss, running as an independent in hopes of holding onto his seat. He will find a long line of Democratic colleagues and friends who now oppose his candidacy.
"It's gotta be pretty uncomfortable," predicted Charles Franklin, a political science professor at the University of Wisconsin at Madison.
Concerns about the senator's return were evident in an internal memo obtained by The Associated Press.
"We should discuss his schedule when he's in DC and whether it makes sense to go to Caucus events, etc. or not," wrote a senior Lieberman aide to several other top staffers.
The memo sought input on 13 likely questions from the media about Lieberman, including whether he or his staff had tried to shore up support among House and Senate colleagues, and what kind of reception he expected from fellow Democrats.
"Once I have the rough answers from you guys I will turn this into a memo for (Lieberman)," the document said.
Top aides were still debating whether Lieberman should join Democrats at the party luncheon. Lieberman will appear at an awards ceremony at the John F. Kennedy Center for the Performing Arts on Wednesday night, but aides provided few other details of his schedule.
Several top Democrats, including party chairman Howard Dean, have abandoned Lieberman, the party's 2000 vice presidential nominee. They back Lamont in the general election, a three-way fight that also includes Republican Alan Schlesinger.
Despite strained relations, Democrats eager to regain control of the Senate will likely want to avoid alienating Lieberman because he could potentially help tip the balance if he wins.
"There's too much at stake to allow personalities to get in the way of power," said Democratic consultant Tad Devine. "There are always hard feelings, but people who make it to the Senate have been through bitter fights and they're used to dealing with it."
Lieberman has said Senate Minority Leader Harry Reid, D-Nev., told him he would retain his seniority and committee seats should he win. Reid, though, said such decisions will be made by the caucus after the fall race.
If Democrats gain the six seats to capture the majority, Lieberman is poised to become chairman of the Homeland Security and Governmental Affairs Committee, a powerful panel dealing with issues such as terrorism.
Lieberman has vowed to stay with the Democratic caucus if he wins a fourth term. Some analysts said as long as Lieberman is seen as a potential winner, he will not be spurned.
"As long as he stays competitive, the Democrats in the Senate aren't going to want to alienate him," said L. Sandy Maisel, director of the Goldfarb Center for Public Affairs at Colby College. "He wants to come back as a Democrat."
However, Lieberman's need to attract independent and Republican support in hopes of winning could worsen his relations with Democrats.
"What he'll need to do to win will only alienate him more and more from regular Democrats," said Democratic consultant Steve McMahon.