Since he declared himself an Independent Democrat, Sen. Joe Lieberman has not been shy about endorsing Republicans. Lieberman, for example, is backing Sen. Susan Collins (R-Maine) over her Democratic opponent, Rep. Tom Allen.

And that’s why his home state — and home district as of late — presents a conundrum for the former presidential candidate.

Rep. Christopher Shays (R-Conn.) endorsed Lieberman in 2006 after Lieberman lost the Democratic primary. But Lieberman endorsed Shays’ Democratic opponent, Diane Farrell, before he lost his party’s nomination.

After the primary, Farrell joined most of her fellow Nutmeg State Democrats to endorse their nominee for Senate, Ned Lamont.

Enter likely 2008 4th district nominee Jim Himes, the Greenwich Democratic Town Committee chairman. Though he faces a primary opponent in Lee Whitnum, who is perhaps best known for divulging her affair with John Kerry to the New York press in the summer of 2004, the Cos Cob businessman has received financial backing from Democratic leadership. Federal election records show Himes donated to Lieberman’s presidential campaign in 2003 and his Senate race in 2005, but also to Lamont’s campaign in 2006.

Lieberman and Shays have aligned on many issues, most notably the Iraq War. Longtime Lieberman adviser Dan Gerstein said the two men have a “long-standing friendship and working relationship.”

Lieberman’s communications director, Marshall Wittmann, concurred, saying in a statement the Senator “enjoys a longtime personal friendship and strong working relationship with Congressman Shays.”

Shays campaign manager Michael Sohn said the campaign was not thinking about endorsements yet, instead focusing on fundraising. But Sohn said the two men have been “good friends for a long time” and “politically, they have a lot of things in common.”

And to top off their working relationship, Lieberman’s office confirmed he recently moved back to Stamford, Conn. — into Shays’ district.

“I know for Joe it’s all about Joe,” said former Lamont campaign manager Tom Swan. “But for [Lieberman] to stab Shays like that after all Shays did for him would be shocking even for Joe.”

More important, perhaps, is the organization that a Lieberman endorsement would bring with it to either candidate in what many consider the most Republican district in the state. State Democratic Party Chairwoman Nancy DiNardo said Farrell could have won last time if New York Mayor Michael Bloomberg, a former Republican turned Independent, did not come into the race last year.

“It’s that he sent people in,” she said. “It’s my understanding that he sent people in to help Sen. Lieberman, but while they were here they helped Chris Shays.”

Furthermore, many suspect Shays will have a much tougher campaign this cycle because his district remains the sole Democratic target in the state, there is an increasingly unpopular war and the presidential race will be at the top of the ticket. Swan predicted that Himes would win the race this time.

“I think Shays benefited from his coordination with [GOP Gov. Jodi Rell] and Lieberman,” he said. “I think most people thought Farrell lost last time because of the campaign she ran.”

Himes’ campaign would not comment directly on whether it is seeking an endorsement from Lieberman.

“Right now the focus of my campaign is on talking directly to the voters about the real priorities a Congressman should have for this District,” Himes said in a statement. “I am confident that we will build a broad base of support among Democrats, unaffiliated and many Republicans who will work together for a responsible end to the war in Iraq, competent national security, responsible health care reform, energy independence and common-sense solutions to our transportation problems.”

The Democratic chairwoman wasn’t sure a Lieberman endorsement would be a positive force for their candidate.

“I honestly don’t know whether or not it would be a plus,” DiNardo said. “I think that Sen. Lieberman’s stand on the war has been very contrary to what a lot of people think in the district, and Chris Shays’ tends to be very similar to how Sen. Lieberman feels.”

However, the manager for Farrell’s 2004 and 2006 campaigns, Adam Wood, disagreed. Wood said Lieberman’s “very strong ties to the 4th district” are a plus for a candidate.

“I think if you look at the outcome, if the outcome of the election in the Senate race in the 4th district is any indication, then I would say it would benefit a Democrat running for Congress to have his endorsement,” Wood said.

Wood said Lieberman’s Senate campaign won in the 4th district, which has the highest number of unaffiliated and Republican voters in the state. It’s also the lone remaining Republican Congressional seat in the state after voters chose not to re-elect his moderate Republican colleagues in 2006, former Reps. Nancy Johnson and Rob Simmons.

“Based on the numbers, that Sen. Lieberman won the 4th district, it would be advantageous,” Wood said. “Part of it was driven by the fact that Sen. Lieberman is from the 4th district, and a lot of his base resides there.”