AUGUSTA – Democrats and Republicans both regard Maine as winnable in this year’s presidential election. But as state history up and down the ticket has shown, the outcome could be influenced – if not dictated – by voters unmoved by the two major parties.

Four years ago Democrat Al Gore carried Maine, defeating Republican George W. Bush by 49.1 percent to 44 percent.

In that contest, Ralph Nader was listed as a Green Independent in Maine and took 5.7 percent of the vote. Other candidates – Reform-labeled Pat Buchanan, Libertarian Harry Browne and Howard Phillips of the Constitution Party – garnered an aggregate 1.3 percent.

This year, the anointed Green presidential candidate is David Cobb, with former Maine gubernatorial candidate Pat LaMarche paired with him as the party’s vice presidential choice. Independents such as Nader need 4,000 to 6,000 signatures from registered voters to qualify for Maine’s November general election ballots.

The deadline is just three weeks away.

“We’re not really sure who’s out there circulating,” said Deputy Secretary of State Julie Flynn.

Despite Gore’s relatively handy win in Maine’s 2000 voting, Democrats and Republicans are treating the state as competitive this time around. The national campaigns established an early presence on the ground and targeted Maine for media advertising.

“I can’t remember when Maine wasn’t a battleground state, can you?” said Patricia Eltman, a consultant to the state’s Democratic coordinated campaign.

Eltman suggests it’s still early to assess Democratic vulnerability to a vote drain toward the Cobb-LaMarche ticket or toward Nader, should he make it onto Maine ballots.

“I would assume there’s a potential for that. … Right now, it’s all so fluid,” she said in advance of the Democratic National Convention in Boston.

But longtime Republican national committeeman Ken Cole sees potential for the Greens or Nader, or both, to siphon votes that otherwise would be cast for a Democratic ticket of John Kerry and John Edwards.

“Absolutely, no question,” said Cole.

As evidence, he cites the U.S. House races of now-Sen. Olympia Snowe and links her re-election wins then to third-party voters who declined to line up behind her Democratic challengers.

“The margin of victory in the 2nd District was the Greens,” Cole said. “Certainly, they were the difference.”

On the Republican side, President Bush is hoping to halt a Democratic string of presidential election victories in Maine that included his own loss in 2000 and his father’s defeat in 1992. In between, President Clinton won Maine as part of his national triumph over Republican challenger Bob Dole.

Both Clinton wins in Maine, in 1992 and 1996, coincided with strong showings by Ross Perot. In 1992, Perot outpaced then-President Bush, the current chief executive’s father, by 316 votes to claim second place.

With Democrats ready to formalize their nomination and Republicans to follow next month, “it’s very close still,” Cole said.

That’s not to suggest most of the electorate is up for grabs, he added.

“Maybe 10 percent of the populace is going to decide the election,” Cole said.

Maine’s willingness to embrace independent candidacies is well known. The state elected two independents to the governorship in modern times.

Nationwide, according to an Associated Press survey of delegates, nearly two-thirds of the delegates to next week’s Democratic convention in Boston say they don’t think Nader will cost Kerry support this fall.

In some states, Democrats have mounted legal challenges to keep Nader off the ballot while some Republican groups have tried to help Nader win ballot placements.

The latest Pew Research Center poll showed Kerry with 46 percent and Bush at 44 percent. Nader was at 3 percent.

In Maine, the latest quarterly survey by Strategic Marketing Services had Bush and Kerry tied at 35.5 percent.

Neither of Maine’s U.S. senators is up for re-election this year, but November voters will face other attractions, including choices for the U.S. House of Representatives and the Legislature.

The National Conference of State Legislatures has listed the contest for control of the Maine Senate as one of the 10 top legislative election battlegrounds in the nation.

The current Democratic edge in the Senate is a bare 18-17. Two cycles ago, Democrats and Republicans split the districts 17-17, with one independent.