In a surprise announcement, moderate Republican Sen. Olympia J. Snowe said Tuesday that she would abandon her campaign for a fourth term -- a contest she was expected to win easily -- because she is frustrated by a polarized atmosphere in Washington.
The move dealt an immediate blow to Republicans hoping to take control of the Senate in November and gave Democrats new hope of winning the longtime GOP-held seat.
"As I have long said, what motivates me is producing results for those who have entrusted me to be their voice and their champion, and I am filled with that same sense of responsibility today as I was on my first day in the Maine House of Representatives," Snowe said in a statement.
"I do find it frustrating, however, that an atmosphere of polarization and 'my way or the highway' ideologies has become pervasive in campaigns and in our governing institutions."
The news came as a surprise to officials in both national parties. Snowe, 65, is in good health and for months had been laying the groundwork for a strong re-election effort, putting together a campaign team, keeping a busy schedule of events in the state and raising campaign money. She had more than $3.3 million in her campaign account at the end of last year, her last campaign finance report showed.
Snowe earned a reputation as an independent voice in her 33 years in Congress but was frustrated by the sharp partisanship and gridlock that has come to characterize the upper chamber recently. She was the only Republican who voted for a version of President Obama's health care overhaul, joining Democrats and casting a vote for the plan in the Senate Finance Committee. She came under intense criticism from conservatives, even after she voted with the GOP to oppose the final legislation.
Snowe epitomized the Northeast centrist Republican, a rare breed in a Senate increasingly dominated by Southern Republicans.
Obama said her career shows what can be done through bipartisanship.
"From her unwavering support for our troops, to her efforts to reform Wall Street, to fighting for Maine's small businesses, Sen. Snowe's career demonstrates how much can be accomplished when leaders from both parties come together to do the right thing for the American people" Obama said.
GOP Sen. Scott Brown of Massachusetts called Snowe a voice of reason in the Senate.
Already there were four Democrats running for Snowe's seat, a group led by former Maine Secretary of State Matthew Dunlap and State Rep. John Hinck. But the vacancy means that Democrats in Maine and Washington may look for a stronger challenger.
Snowe is married to former Maine Gov. John R. McKernan Jr. She was widowed at 26 when her first husband, state Rep. Peter T. Snowe, died in a car crash. She won a 1973 election to fill his vacant seat. Five years later, she was elected to the U.S. House, where she served for 16 years before winning a Senate seat.