President Obama issued a statement praising Snowe’s bipartisanship.

“From her unwavering support for our troops, to her efforts to reform Wall Street, to fighting for Maine’s small businesses, Senator 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.

Obama noted that Snowe, elected to the state House in 1973, became the first woman in American history to serve in both houses of a state legislature and both houses of Congress. 

While most politicians commenting on Snowe’s decisions applauded her service, Andrew Ian Dodge – a Tea Party activist and one-time primary challenger who now wants to run as un-enrolled – did not.

“The worst thing the party could do is nominate ‘a business as usual politician’ or ‘another go-along-to-get-along politician’ who won’t challenge the bankrupt economic policies that have prolonged the recession and unemployment in Maine,” Dodge said in a statement. “Now, more than ever, it is time for a new voice to represent Maine in DC, not another professional politician.”

8:09 p.m.

State Rep. Jon Hinck, one of four Democratic candidates running
for Snowe’s seat, said Sen. Olympia Snowe’s withdrawal from the race does not change his course.

Hinck, D-Portland, said his campaign has focused on differences between him and Snowe and he will continue to advocate his economic and environmental priorities.

“Although my campaign for the United States Senate has highlighted some of the areas where we disagree, I never question, never doubt Senator Snowe’s commitment to the people of our great state,” Hinck said.

Also seeking the Democratic nomination are: Matthew Dunlap of Old Town, a former Maine secretary of state; state Sen. Cynthia Dill of Cape Elizabeth; and home builder Benjamin Pollard of Portland.

7:48 p.m.

Fellow Republican Sen. Susan Collins of Maine called Sen. Olympia Snowe’s decision not ot seek re-election a complete surprise.

“Nobody can replace Olympia in the Senate,” she said. “It’s going to be a real void.”

7:20 p.m.

Republican Scott D’Amboise, a southern Maine small businessman, is now the only remaining candidate in the Republican primary for U.S. Senate and says he plans to stay the party’s nominee.

Sen. Olympia Snowe’s announcement that she won’t seek re-election comes a week after a third Republican candidate, Andrew Ian Dodge, dropped out of the race.

Maine requires candidates collect nearly three-thousand signatures from registered Republican voters to gain access to the ballot, he said in a statement. Each signature must be certified by the town clerk from the voter’s resident town prior to filing the signature with the Secretary of State, he said.

“With Maine’s complicated signature process, it is doubtful that any other Republican could collect the requisite number of signatures to appear on the ballot before the March 15th deadline no matter how much money they spent,” he said.

7:07 p.m.

Rep. Mike Michaud, Democrat representing in the 2nd district, said he was seriously considering running for the seat being vacated by Republican Sen. Olympia Snowe.

“I’ve been extremely humbled by the outpouring of encouragement I’ve received from all over our state to run for the Senate,” said Michaud, who has served five terms in the House.

Snowe’s announcement not to run for re-election is expected to attract top figures in both parties.

6:44 p.m.

Sec. of State Charles E. Summers, Jr. issued a statement calling Snowe – who he once worked for – “the epitome of public service.”

“Her dedication to Maine and her people is legendary and second to none,” said Summers, who served as the state director for Snowe from 1994 to 2004.

Summers, who has already been mentioned as a possible successor to his former boss, made no mention in his statement about whether he would pursue the seat or make another run for Congress if the First District seat opens up. He has run unsuccessfully for Congress three times previously.

6:30 p.m.

Rep. Chellie Pingree, D-1st District, praised Sen. Olympia Snowe’s “independence and dedication to Maine” while saying she will evaluate in the coming days whether to run for the seat.

Leaders from both parties are expected to consider running for the open seat.

Meanwhile, Gov. Paul LePage called Snowe a tremendous leader and a tireless advocate for the state.

The decision by Snowe, the favorite to win in November, that she will not seek re-election has created a void in the political landscape that many of the state’s aspiring politicians will seek to fill.

Because Snowe is one of the few Republican centrists in the Senate and often represents a swing vote on key legislation, the race to fill her seat willl have national implications.