Washington - As he moves into what he says his colleagues refer to as "the afterlife," retiring U.S. Sen. Joseph Lieberman, D-Conn., has no shortage of commentary on the institution he is leaving behind.

"This much I can say, unfortunately, with confidence - that the last two years have been the most partisan, uncompromising and unproductive of my 24 years here," Lieberman reflected during a recent interview in his Senate office.

As he prepares to sell his house in Washington and return to Stamford - where he grew up - to be near family, Lieberman expressed the hope that his time in Congress ends with a bipartisan agreement to avoid the so-called "fiscal cliff."

Lieberman came to Washington after serving in the state Senate for a decade and spending six years as the state's attorney general. He was a "transformational figure" for the latter, observed U.S. Rep. Joe Courtney, D-2nd District. Through Lieberman's influence, Courtney said, the attorney general's office evolved from being seen as part-time public service to a "high profile" voice in issues such as consumer and environmental protection.

Now, Lieberman is ending an unusual, quarter-century journey on Capitol Hill: Elected in 1988 as a Democrat and nominated as his party's vice-presidential candidate in 2000 (the first Jewish-American ever placed on a major party's national ticket), he is now an independent who counts several Republicans among his closest friends and allies.

One Connecticut Republican, former 2nd District Rep. Rob Simmons, said Lieberman's "greatest achievement was that he placed good public policy over party politics."

Simmons, who represented eastern Connecticut from 2001 to 2007, recalled meeting with Lieberman, then-Gov. M. Jodi Rell, and a group of state legislators in New London on May 3, 2005. On that morning, the group received the announcement that the Naval Submarine Base in Groton was to be closed.

"He was initially stunned, as we all were," said Simmons in a telephone interview. But Lieberman "quickly made the decision that he would work with all of us in the group to save the base." Simmons was impressed that Lieberman, a Democrat at the time, decided to work with a Republican president, governor, and member of Congress rather than leave the issue to the other party to sort out.

"His willingness to stand with us was really exceptional and outstanding, and that's the way he was," said Simmons. The group questioned some of the data that had gone into the decision to close the base, maintaining that it would actually not save money to close it. In the end, the group won the battle after a hearing held by the Defense Base Closure and Realignment Commission (BRAC).

Simmons' successor, Democrat Courtney, also remembers Lieberman's work to save the Groton base - with "the economy of southeastern Connecticut hanging in the balance" - as one of the senator's most significant achievements for the state. Courtney, who attended a hearing about the base's future, said Lieberman's summation "was the really the finest speech I've ever seen."

Environmental protection, 9/11 commission

While the rescue of the Groton submarine base is what sticks with the eastern Connecticut legislators, Lieberman cited his environmental protection efforts as among his major achievements on behalf of his home state.

Early in his Senate career, Lieberman worked with congressional colleagues to create a Long Island Sound office within the Environmental Protection Agency, which has identified environmental problems within the Sound. Over the past decade, he has sponsored legislation that seeks to address these issues.

He was also involved in the creation of Connecticut's first national park: Weir Farm National Historic Site. Located in the western Connecticut towns of Ridgefield and Wilton, the 60-acre farm was home to three generations of artists and a center for early American Impressionism.

Calling Weir Farm a "beautiful site," Lieberman noted that "it was going to be lost to development, and we were able to protect it."

Nationally, Lieberman is known not for these efforts but for "the work that I've had the opportunity to do after 9/11 to keep our country safe and protected from another terrorist attack," as he put it.

That work - including his involvement in creating the Homeland Security Department and the 9/11 commission - secured his reputation as a lawmaker who looks beyond partisan labels.

Bipartisan alliances

While Lieberman came to Washington as an independent-minded Democrat, he said the 2006 Senate election motivated him even further to seek bipartisan alliances.

Just two years after he unsuccessfully sought the 2004 Democratic presidential nomination, Lieberman was narrowly denied renomination to the Senate by Ned Lamont, a wealthy businessman who made an issue of Lieberman's support of the war in Iraq. Lieberman branded himself an "Independent Democrat" and defeated Lamont, the official Democratic Party nominee, in the general election.

"When the people of Connecticut were really great to me after I lost the Democratic primary and re-elected me, I wasn't elected just with Democratic votes," explained Lieberman. "I got votes from Republicans and independents, and so my obligation was to do what I thought was right for my constituents overall, for my state and for my country-not that I needed to walk a party line if I didn't agree with it."

Lieberman's subsequent relationship with the Democrats, both on Capitol Hill and at home, has been rocky at times. He caucuses with the Democrats and votes with them on almost every issue outside of foreign policy. But his decision to run against Lamont after losing the party's 2006 Senate nomination earned him a rebuke from then-Democratic National Committee Chairman Howard Dean.

Two years later, Lieberman's endorsement of the 2008 Republican presidential candidate, Arizona Sen. John McCain, led some Democrats to demand that Senate Majority Leader Harry Reid strip Lieberman of his chairmanship of the Homeland Security and Governmental Affairs Committee. (Lieberman held onto the post.)

Close allies

Republicans are now among Lieberman's closest allies in the Senate. He has worked and traveled with McCain and Sen. Lindsey Graham, R-S.C., on issues of foreign policy and national security, frequently visiting war-torn areas such as Iraq and Afghanistan.

Another Republican friend is Sen. Susan Collins of Maine, a moderate who chaired the Homeland Security and Governmental Affairs Committee from 2005 until 2007, at which point Lieberman took over the chairmanship when the Democrats won control of the Senate. Collins endorsed Lieberman for re-election during his 2006 bid as an independent, and Lieberman repaid the favor by endorsing Collins when she faced a competitive re-election contest from a Democratic House member two years later.

"I'll never forget when I was losing the chairmanship because of the change in control, Joe leaning over to me and saying, 'Don't worry, Susan. All that will change is that you'll pass me the gavel,'" recalled Collins in a floor speech this month paying tribute to Lieberman.

As chairman of the committee, Lieberman asked the senators to be seated not by party but in an interspersed manner. This practice, unique among Senate committees, "sends an important symbolic message that it's not us against them," said Collins in a telephone interview.

She called Lieberman's consistent rejection of "don't ask, don't tell" - a policy that barred openly gay men and lesbians from serving in the military - his greatest achievement as a senator and an example of his integrity.

"From the very beginning, Joe was convinced that that policy was unfair and discriminatory," said Collins, who broke with her own party to seek repeal of the policy. "But back in the Clinton era, he was a lonely voice in arguing that 'don't ask, don't tell' was the wrong policy and unfair to patriotic gay and lesbian citizens."

After a lifetime as what Simmons called a "career politician who brings dignity to the word," Lieberman plans to keep his voice in public policy after retirement.

"I'm sure I'll start doing op-eds next year," he said. He's also considering writing a book or two.

"I've been really lucky, I've had just amazing opportunities to serve," he explained, "and I've had some extraordinary experiences which I'd like to record for history."