In a widely expected move, independent Senator-elect Angus King of Maine announced Wednesday that he will join the Democratic Senate caucus, bringing the Democrats to a 55-senator majority in the new Congress, which convenes in January.

A former governor of Maine, King ran as an independent to fill the Senate seat being vacated by centrist Republican Sen. Olympia Snowe.

J. Scott Applewhite / AP

Sen.-elect Angus King, I-Maine, center, the former governor of Maine, arrives on Capitol Hill in Washington, Tuesday, Nov. 13,2012.

“The outcome of last week’s elections in some ways makes this decision relatively easy,” King told reporters at a Capitol Hill press conference. “In a situation where one party has a clear majority and effectiveness is an important criteria, affiliating with the majority makes the most sense. The majority has more committee slots to fill, has more control over what bills get considered and more control over the Senate’s schedule.”

King said he’d conferred with Senate Majority Leader Harry Reid and former Senate Majority Leader George Mitchell, a Maine Democrat, before making his decision, but not with Senate Republican Leader Mitch McConnell. He did confer with Sen. Roy Blunt, R-Mo., the Senate GOP conference vice chairman.

He said his conversations with Reid and with independent senators Joe Lieberman of Connecticut and Bernie Sanders of Vermont, who caucus with the Democrats, reassured him that “my independence would be respected and that no party-line commitment would be required or expected.”

King said he’d asked Reid for a spot on the Senate Finance Committee, its tax-writing panel, “but there were no promises made… He pointed out to me that it took Sen. Kerry 14 years to get on the Finance Committee so it might be somewhat unlikely for a first-year senator to achieve that.”

He said that “by associating myself with one side I am not in automatic opposition to the other.”

On the question of the Senate filibuster rule -- which allows the minority party to insist on 60 votes before a bill can move forward or a nomination come up for vote -- King said that although he represents a small state and the filibuster is “designed to protect the interests of small states,” that “its use in recent years has been excessive and I hope to talk with other senators who are more expert in this matter to find a solution that would limit its use as a tactic of delay and prohibiting action, but at the same time protect the interests of the states."

Since President Barack Obama was first elected, Republicans have used the filibuster to stymie some of his nominees and to make it impossible to enact tax increases proposed by the Democrats.

Maine Republican Olympia Snowe says the Senate spends too much time in political battle and not enough on solving problems, and more than a few of her colleagues agree.

Snowe, the Senate's most liberal Republican, found herself in a familiar spot Thursday as the only member of her party to join with Democrats on a politically freighted vote. This time, it was a vote to affirm an Obama administration directive requiring employers to provide contraception coverage to their workers regardless of religious or ethical concerns.

The vote, originally demanded by Republicans in a political battle that Democrats came to embrace, provided ample fodder for political ads but had nothing to do with an underlying highway bill. That measure continues to twist in the wind despite widespread support, trapped in a divisive, polarized Senate that rarely seems to legislate and often seems incapable of tackling politically challenging problems.

So Snowe, 65, is leaving at the end of the year, voicing frustration that the Senate is simply too polarized and that she doesn't know whether she could be "productive" in a fourth Senate term.

"It's a reflection of the political dynamic in America, where we don't look at America as a whole. We look at it through the red and blue prism," Snowe said in an interview. "And so it becomes more divisive and I think ultimately has manifested itself in the Senate and an overall process that lends itself to dysfunction and political paralysis that doesn't allow problems to be solved."

Snowe's departure continues a steady exodus of the chamber's moderates. Centrists like Ben Nelson, D-Neb., and Joe Lieberman, I-Conn., are also leaving, following on the heels of the recent departures of Evan Bayh, D-Ind., Blanche Lincoln, D-Ark., and Republican-turned-Democrat Arlen Specter of Pennsylvania.

"People in the center are increasingly vilified by the far left and the far right," said Sen. Susan Collins, Snowe's home-state GOP colleague. "We used to be applauded for bringing people together to solve problems. Now we tend to be criticized by both sides."

Snowe is leaving even though she would have been poised to take the helm of the Commerce Committee if Republicans take control of the chamber. She also serves on the Finance Committee, which has sweeping jurisdiction over health care, taxes and trade.

There's little real legislating going on in the Senate these days, however, as the chamber lurches from one politically staged vote to another.

The chamber hasn't debated a budget since 2009. Annual spending bills are passed in huge omnibus measures with little discussion, much less amendment.

"There's a rank-and-file rebellion brewing here," said Sen. Lindsey Graham, R-S.C. "Most people who come to the Senate work hard to get here and have done things in their lives of accomplishment. And I think a lot of us are getting tired of sitting around looking at each other."

"This body is supposed to be a great deliberative body. It's supposed to do what's right for the nation," said Sen. Dianne Feinstein, D-Calif. "If everything here is political, it it's to score points rather than solve problems, then what good is the United States Senate?"

Added Feinstein: "It's a heartbreak. And it's a heartbreak to lose (Snowe), candidly."

Republicans say Majority Leader Harry Reid, D-Nev., is too quick to employ parliamentary maneuvers — used frequently by leaders in both parties — to block Republicans from offering and getting votes on their ideas. And they charge that Reid, when he does schedule votes, is more interested in painting Republicans into a political corner, as he did during last fall's debate on extending a 2 percentage-point cut in the Social Security payroll tax and on a tax surcharge on millionaires pressed by Democratic leaders.

Democrats, who control the Senate with 53 votes, counter that Republicans require Democrats to produce 60 votes for virtually everything and deny Reid approval for parliamentary steps that were considered routine just a few years ago. A long roster of presidential nominees remains stuck in limbo, blocked by Republicans.

"It's supposed to be deliberative. Instead now the floor is just a wasteland of quorum calls and lurching from one filibuster to another," said the Senate's No. 2 Democrat, Dick Durbin of Illinois. "It really, I'm afraid, has damaged the institution."

Since it takes 60 votes to do anything, virtually nothing passes that doesn't have the approval of Minority Leader Mitch McConnell, R-Ky. What that often means is that much of the real legislating is done by a handful of top leaders and committee chairmen, leaving most senators out in the cold.

After a meeting at the White House on Wednesday, GOP leaders emerged optimistic that the House and Senate would work together more productively on bipartisan jobs and energy legislation.

Snowe sounded unconvinced in a statement announcing her retirement.

"Unfortunately," she said, "I do not realistically expect the partisanship of recent years in the Senate to change over the short term."