Washington - Sen. Joe Lieberman, a Connecticut independent and onetime Democrat known for frequent splits with his former party, has found a fresh way to stand apart: He's the only retiring senator with a solid chance to leave a mark on policy this year.

Lieberman may bring two significant bills to the floor, while nine other departing senators will have few similar opportunities before their terms end. Senate Budget Committee Chairman Kent Conrad, D-N.D., won't lead debate on a budget plan because Senate Democrats decided not to go through the exercise this year. Jeff Bingaman, D-N.M., chairman of the Energy and Natural Resources panel, ends his career as lawmakers trade blame over high gas prices with no energy agreement in sight.

Lieberman is working on a measure to bolster the nation's computer defenses and another overhauling the financially struggling U.S. Postal Service. While neither measure grabs the headlines, if Lieberman can help navigate opposition in the Democratic-run Senate and Republican-dominated House they would be top congressional accomplishments in an election year.

"I'm excited about the opportunity to get some significant things done in my final year here," said Lieberman, first elected to the Senate in 1988. "If I can get those bills out of the Senate, then I have a chance on both."

Lieberman, chairman of the Committee on Homeland Security and Governmental Affairs, has the advantage of sponsoring bills that avoid the political polarization that has doomed other Senate work, said Vincent Moscardelli, a political science professor at the University of Connecticut in Storrs.

"These are the only issues left for people who want to stake out the middle," Moscardelli said.

Lieberman, 70, often moves between the parties on issues, though he hasn't entirely found a place in either. The 2000 Democratic vice presidential nominee made history as the first Jewish candidate on a major-party presidential ticket. He became an independent in 2006 after losing his Senate primary to a challenger who attacked his support for the Iraq war.

Lieberman caucuses with Democrats. He angered party leaders when he endorsed Arizona Sen. John McCain for president at the 2008 Republican National Convention. Some Democrats wanted to strip him of his committee chairmanship, though he kept it with President Obama's support.

Later, he withheld support for Obama's health care overhaul until Democrats dropped a government-run "public option" to expand coverage.

Whether he leaves the Senate on his own terms isn't assured. His two final bills are hitting snags in the Senate, and House passage isn't assured.

The Postal Service bill would authorize cost-cutting steps to save it from bankruptcy in an era of email. The measure would provide more revenue, in part by allowing the Postal Service to ship wine and beer and boost some rates. It would cut billions of dollars of mandated pre-payments to its retiree health benefits fund.

The Postal Service, which wants to end Saturday mail delivery and close as many as 3,700 post offices, would have to keep six-day service for at least two more years and go through a designated process to decide which facilities to close.

Last week, a Senate vote to consider the postal bill fell nine votes short, so it won't come up until after a two-week April recess. Some senators say rural states aren't guarded enough against post office closures and reduced mail delivery.

Lieberman said he and other bill sponsors want to find a "sweet spot" with opponents by imposing even tougher reviews of postal office closures in an amendment they'll offer.

Lieberman said enactment of the cybersecurity bill would be an achievement in a career that included helping to create the Department of Homeland Security after the Sept. 11 terrorist attacks. His measure seeks to strengthen computer defenses for banks, power grids and telecommunications firms to prevent an attack.

He wants to give the Homeland Security Department the ability to identify critical computer networks, set rules for their operators and require companies to prove their networks are secure or face penalties.

McCain and other Republicans say the cybersecurity bill would be too tough on the industry. A McCain proposal would avoid new industry rules while promoting information-sharing incentives such as protection from lawsuits. The two are negotiating on a possible compromise.

Senate Majority Leader Harry Reid, D-Nev., decided consultations on both Lieberman bills were getting "endless" and will allow both to be worked out on the floor through amendments, said Reid spokesman Adam Jentleson.

"Neither is a lock to pass," Jentleson said. "The processes on both will be pretty intricate."

Lieberman gave credit for progress on the measures to his working relationship with Maine Sen. Susan Collins, the panel's top Republican and a co-sponsor of both bills. The two often join together on legislation, including the 2010 repeal of the "don't ask, don't tell" policy barring gay people from serving openly in the military.

"We've developed just an extraordinary working relationship," he said. "There's just a lot of trust and transparency."

Illinois Sen. Dick Durbin, the No. 2 Democratic leader, said Lieberman's relationship with party colleagues is "extremely positive" even after the past rifts. Sen. Lindsey Graham, R-S. C., a close ally of Lieberman, said he gets results because of his personal relationships and mastery of the details of government.

"That's the formula for being an effective senator, and that's Joe in a nutshell," said Graham. "He's passionate and he's knowledgeable. Whether or not you agree with him on something, I think he's universally respected for being his own guy."

Lieberman said he has few regrets about the controversies in his Senate career, including his McCain endorsement and support for the Iraq war.

"I think I'm going to enjoy just watching" this year's presidential campaign, he said, and has no plans for a major- party endorsement.

Although his support for the war "caused me a lot of political heartache, I feel good that I stuck with the war in Iraq even when it got to be unpopular," Lieberman said. "I didn't want us to essentially declare defeat and leave."

_ With assistance from Michelle Jamrisko and Chris Strohm in Washington.

AP-WF-03-31-12 1616GMT