Maine Republican Senator Olympia Snowe has announced her retirement.

A moderate Republican, who has often voted with Democrats in the Senate cited the extreme partisanship of recent years as her reasoning.

In a statement Snowe said, “Unfortunately, I do not realistically expect the partisanship of recent years in the Senate to change over the short term. So at this stage of my tenure in public service, I have concluded that I am not prepared to commit myself to an additional six years in the Senate, which is what a fourth term would entail.”

Notice of her retirement could be a “major setback for the GOP’s efforts to regain a majority in the Senate.” With Maine being a blue state, Snowe was considered as a moderate, to be the GOP’s only hope to hold the seat.

Among the names mentioned as possible replacements on the ballot for the GOP: 2002 gubernatorial candidates Peter Cianchette, 2010 gubernatorial candidate Steve Abbott, state Treasurer Bruce Poliquin, state Attorney General Bill Schneider, and Jock McKernan, Snowe’s husband and the state’s former governor. Businessman Scott D’Amboise was already challenging Snowe in a primary.

On the Democratic side, Reps. Chellie Pingree (D) and Mike Michaud (D) could run, as well as former congressman Tom Allen (D), who unsuccessfully challenged Sen. Susan Collins (R-Maine) in 2008.

The filing deadline is fast approaching: March 15.

Progressives are already crowing that Snowe is retiring and it can indeed be a win/win for Democrats, but let’s celebrate when we win her seat. Snowe has always been an ally on women’s issues, and with the surge in the war on women, we very much need a pro-choice, pro-women’s issues vote to replace her.

On the flip-side Democrats are losing their most moderate member, Senator Ben Nelson of Nebraska. Former Senator Bob Kerrey is said to be reconsidering running for Nelson’s seat.

Image: Democracy Corps

For the first time since the 2010 election, Democrats have taken the lead in the congressional vote and this poll shows that third-party defections on the presidential ballot could prove devastating for the Republicans, according to a new poll out Friday.

Moreover, the intensity gap has shifted in the Democrats’ favor and Democrats have moved to parity on the economy after 28 months in deficit, the Democracy Corps poll finds.

More than half of all voters (53 percent) say that the more they watch the Republicans in Congress, the less they like what the Republicans have to offer; only 39 percent say they like it more — a 14 point margin. The country is equally repelled by the Republican presidential contest (53 to 38 percent). The style of their politics and governance is driving away independents. And more than half of white non-college voters, who were key to Republicans’ wins in 2010, do not like what the Republicans in Congress are offering — a staggering result, the pollsters say.

Key findings:

• For the first time in two years, Democrats are winning the congressional ballot (47 to 44 percent), the result of a major shift among independents. Democrats are now winning independents by 2 points — a net 9-point shift among independents since October and a net 19-point shift since August. In June, Democrats were losing independent men by a margin of 29 points. That gap has closed to just one point. In 2010, Democrats lost seniors by a 23-point margin. That gap has closed to just 7 points.
• The Republicans have lost their advantage on the economy. The parties are now even on which party would do a better job on the economy, a net 7-point shift since October. While most improvements in this poll are due to Republicans faltering, here Democrats have gained 5 points on trust to handle the economy.
• John Boehner’s favorability has fallen off significantly — 44 percent now give the House Speaker a negative rating with three in 10 voters giving him a very negative rating (under 25 on our 100-point scale.)
• Two-thirds of all voters now say they disapprove of this Republican Congress and its approval rating has hit a new low in our tracking — 26 percent. The decline has come from a complete drop-off of those who “strongly approve” of this Republican Congress — down to 8 percent, also the lowest in our tracking.

The Presidential Contest Full of Peril

The race for president remains very close, though showing the first signs of improvement for Barack Obama. With his approval rating at 44 percent and vote at 47 percent, you have a close contest. But Obama’s strong support is up 5 points, has more winnable voters than Romney and has made some important recent gains with key swing groups. Obama is now winning 40 percent of white-non college voters, his highest total among that group in a year. Among independents, Obama now trails by just 3 points—cutting his deficit in half since October.

Romney is not popular -– only 31 percent of all voters, and only 27 percent of independents, give him a warm, favorable rating. Obama, on the other hand, remains personally popular, with nearly 50 percent giving him a warm, favorable rating. As a result, Mitt Romney has not been able to energize voters. Voters, especially Republicans, are ready to bolt to independent candidates in large numbers — indeed, remarkable numbers.

This new poll shows that as a third-party candidate, Republican Ron Paul would take 18 percent of the vote in a match-up against Obama and Romney. Almost all of this comes at Romney’s expense. Nearly tied in a head-to-head match-up against the president, Romney’s vote plummets when Paul is added to the ballot, losing 12 points of his vote share.

The libertarian-leaning Texas congressman, Paul has neither announced any plans for a third-party campaign if he should lose the GOP nomination, but neither has he entirely closed the door on the idea.

The poll results are based on a national survey of 1,000 likely 2012 voters conducted January 8-11, by Greenberg Quinlan Rosner Research for Democracy Corps. Its overall margin of error is +/- 3.1 percentage points.

Scott Nance is the editor and publisher of the news site The Washington Current. He has covered Congress and the federal government for more than a decade.