PORTLAND, Maine -- With her entire staff on the Senate floor and her husband watching from the gallery, Sen. Olympia Snowe on Thursday delivered a plea to her colleagues to overcome "excessive political polarization" to work together to reach consensus on the "fiscal cliff" and other important issues.

The Maine Republican, known for her fierce independence, lamented that the Senate has evolved into something akin to a parliamentary system where members vote in party blocs, promoting corrosive partisanship that has led only to gridlock.

"I'm so passionate about changing the tenor in Congress because I've seen that it can be different. It hasn't always been this way. And it absolutely does not have to be this way," she said.

Snowe shocked the political establishment in late February when she abruptly ended her bid for a fourth term, a race that she would have easily won, citing partisan gridlock.

Speaking from the Senate floor in Washington, D.C., Snowe took time Wednesday to thank the people of Maine for placing their trust with her during 34 years in Congress, including three terms in the Senate. Snowe, who was orphaned at age 9, is the third-longest-serving woman in congressional history.

Snowe said she inherited a legacy of bipartisanship and independence from the late Sen. Margaret Chase Smith, who is remembered for her "Declaration of Conscience" speech attacking McCarthyism.

On Thursday, Snowe focused on something that she found to be important more than 60 years later -- a lack of civility and excessive partisanship that she says prevent the Senate from accomplishing the Founding Fathers' ideals.

She repeatedly pointed to examples of senators working together in the past.

"Our problems are not insurmountable, if we refuse to be intractable. It is not about what's in the best interests of a single political party, but what's in the best interests of our country," she said.

Snowe said she's not leaving the Senate because he's ceased believing in the institution. Instead, she said she wants to work from outside to encourage bipartisanship and consensus.