AUGUSTA — Sen. Olympia Snowe’s announcement that she will retire sent shock waves through Maine’s capital late Tuesday.

Democratic and Republican party leaders were equally stunned by the news, which set off tributes to Snowe and intense speculation about who will run for her seat and what the ripple effect will be on Maine’s two congressional races.

While Democrats were excited about the new possibilities, Republicans were clearly disappointed by the decision. Members of Snowe’s party were blindsided with a little more than two weeks before the filing deadline for new candidates.

“The ink hasn’t dried off her announcement (to run),” said lobbyist Josh Tardy, former House Republican leader. “On all sides, it blows (the race) wide open. The Democrats may take another focus on it and increase their field. It will create a frenzy on the Republican side.”

Democratic leaders cited Snowe’s long service to the state even as they considered the political impact.

House Democratic Leader Emily Cain, D-Orono, praised Snowe as “a powerful role model for women around our nation and around the world.”

Democrats already have three strong candidates running for Snowe’s seat, Cain said, but there could soon be more.

“I think with someone who has served as long as Olympia Snowe has, there are many doors that open when an announcement like this comes,” Cain said.

The three declared Democratic candidates are Sen. Cynthia Dill, D-Cape Elizabeth, Rep. Jon Hinck, D-Portland and former legislator and secretary of state Matthew Dunlap of Bangor.

Snowe also was facing a Republican rival for her seat, Scott D’Amboise. D’Amboise issued a statement saying he is the presumptive Republican nominee because there is so little time for other candidates to qualify.

“I respect Senator Snowe’s decision, and look forward to facing the Democratic nominee in the fall,” he said.

A candidate needs 2,000 certified signatures by March 15 to qualify and, while time is short, all observers now expect the field to grow and shift. Speculation swirled from Maine to Washington, D.C. Tuesday about who will seek the powerful post.

U.S. Rep. Chellie Pingree, D-1st District, thanked Snowe for her service and said she is considering a run for the seat.

U.S. Rep. Mike Michaud, D-2nd District, also praised Snowe and said he was considering a run, too.

A decision by either of them to run will create a scramble to replace them in the House.

Maine State Senate President Kevin Raye, R-Perry, a former Snowe aide for more than 17 years, who is running for the 2nd District seat said he also will consider a run for the open Senate seat.

Other Republicans mentioned as possible candidates included Secretary of State Charlie Summers and former ambassador and gubernatorial candidate Peter Cianchette.

Eliot Cutler of Cape Elizabeth, an independent who narrowly lost the race for governor in 2010, also was widely mentioned as a possible candidate.

“I think we’re looking at a whole new race now,” Ron Schmidt, associate professor of political science at the University of Southern Maine in Portland.

Schmidt said he was amazed by the announcement and said it immediately draws national attention to Maine’s senate race.

With Snowe running for re-election, the seat had been considered safe for the Republican party, he said. Now it is now much more of a toss-up.

“I would have said before there were five, or at top seven, Senate seats in play (nationwide). This makes another one.”

In most of the other open races, Democrats are trying to hold onto the seats. “Here, all of the sudden, they have a chance to pick one up,” Schmidt said.

Open scramble

Although there are a lot of possible scenarios, Maine’s political parties will have to sort out quickly who will run for what.

Snowe’s decision leaves other candidates only about two weeks to get their signatures turned in to qualify for the ballot, said Sen. Jonathan Courtney, R-Springvale.

“It opens up a lot of opportunity for people,” Courtney said. “Certainly Olympia has been a terrific party builder over the years. Whether you agreed with her or not, she has worked tirelessly for the party.”

Courtney had decided earlier this year against a run for the 1st District seat, and said he was not prepared to comment on whether he would run for the Senate. He said he expects a lot of interest on the Republican side.

“It’s a U.S. Senate seat,” he said. “Washington is clearly broken. You look at the approval ratings for members of Congress and it’s in the single digits. We need a new approach.”

GOP Party Chairman Charlie Webster said he had spoken to Snowe several times about her frustration with working in Washington.

“She’s always been a consensus builder,” he said.

Webster said he did not know who would step in, but that the party has a “farm team” of good candidates who can fill the spot.

“It’s going to be an interesting couple of weeks,” he said.

Lizzy Reinholt, a spokeswoman for the Maine Democratic Party, said there are a lot of conversations going on about who will run.

“There are so many different possibilities right now,” she said. “I think in the next few days we’re going to see quite a few names come forward.”

Hinck, the Democratic state representative who is already running for the seat, said he can understand why Snowe got frustrated.

“I’ve often though it seems to me she must be in an untenable position. The word moderate (to describe Snowe) is accurate in my opinion.” But, he said, “her party as become increasingly extreme.”

Hinck said he and the other candidates already in the race have an advantage.

“The people who would be willing to stand up to run against Olympia Snowe, the titan, have already demonstrated their mettle,” he said.

“I’m thrilled that finally there’s a realistic opportunity to make some different choices for Maine in the U.S. Senate,” said Sen. Dill, the state senator running for the seat. “I’m pleased, like so many of Maine’s leaders, she is existing on a graceful note.”

Gov. Paul LePage issued a statement thanking Snowe for her service.

“I was saddened to learn today that Senator Olympia J. Snowe will not seek re-election for United States Senate,” he said. “Senator Snowe has represented the state of Maine for more than three decades with integrity and has been a tremendous leader and a tireless advocate for the people of Maine.”

Secretary of State Charles Summers issued a statement saying he was “deeply saddened” by Snowe’s decision. “Her dedication to Maine and her people is legendary and second to none.”