AUGUSTA, Maine — With a week to go, tens of thousands of Mainers already have cast votes for their senators and representatives to the state Legislature, and the Democrats are confident their get-out-the-vote effort, both now and on Election Day, will make a difference when all the votes are counted.

Democrats, who currently control both the House and Senate, have expanded their traditional “unified” campaign that works for election of all Democratic Party nominees. They have opened 34 offices around the state, with both paid staff and volunteers working to identify likely voters who will support presidential nominee Sen. Barack Obama of Illinois and all the nominees down through the ballot to legislative candidates.

“The unified campaign the Democrats have put together is very, very impressive,” said Colby College government professor Sandy Maisel. “It will help all the Democrats on the ballot.”

Republicans also are mounting a get-out-the-vote effort, but it is not as large or as well-funded as the Democrats’ effort. Traditionally, the GOP has not put as much emphasis on the “ground game” of politics with voter identification and get-out-the-vote efforts and put more effort in the “air game” of advertising, said Bowdoin College government professor Chris Potholm.

“In a close race, the ground game can make a difference,” he said. “A few percentage points but not a big difference.”

What is never certain is how much of the efforts in the presidential and U.S. Senate races will “trickle down” to the state legislative races, what politicians call the “coat tail effect.”

In the House, GOP floor leader Josh Tardy, R-Newport, acknowledges it is a long shot for his party to take control of the House. The Democrats currently hold 90 of the 151 seats to the GOP’s 59, along with two independents.

Thirteen Democrats and just two Republicans are term limited, but the GOP does not have candidates in 15 seats, while the Democrats have candidates in all but two contests.

“The fact is that it was less than a total of 1,400 votes that divided control of the Legislature in the last election,” Tardy said. “There were a lot of races decided by a handful of votes.”

Both Tardy and House Majority Leader Hannah Pingree, D-North Haven, agree that with each district representing less than 9,000 people, a good candidate from any party, or an independent, can win any of the 151 seats. They say even though some districts lean to one party or another, the adage “all politics is local” holds true.

“We have seen many races where a good candidate has surprised us,” she said, “and upset incumbents in some races. We are taking no races for granted.”

The GOP is hoping they can pick up a few seats currently held by Democrats by having former lawmakers run for those seats. Democrats are banking that their unified campaign will pay dividends in some open House seats, such as those in Bangor.

In the Senate, both party leaders are frank that half a dozen contests will determine control of the 35 seat chamber. Democrats hold an 18 to 17 seat advantage, the same as going into the last election. Eight years ago, the parties tied with an independent holding the balance of power.

There are four Democrats and two Republicans in the Senate termed out this year. In District 22, most of Knox County, two current representatives, Republican Chris Rector of Thomaston and Democrat David Miramant of Camden, are battling over an open seat, and both parties see it as a close race.

Another battleground district is in southern York County where incumbent Democrat Peter Bowman is being challenged by former Republican Sen. Mary Andrews. Both parties see that as a close race.

Senate Majority Leader Elizabeth Mitchell, D-Vassalboro, said that while there are several close races, she “feels good” about how all of the Democratic candidates are doing and is “optimistic” the Democrats will maintain control of the Senate.

“We have more possible wins than I ever dared to dream of,” she said. “As majority leader, though, I remember that 18 is the magic number and that is what I am focused on.”

She said while some races are close, she believes Democrats are being bolstered by the “rising tide” of support for Obama as a result of the economy. The former House speaker said Democrats may pull off more than one surprise win in legislative races.

Senate GOP floor leader Carol Weston, R-Montville, agreed a presidential election year has “a lot of unknowns” but said the GOP Senate candidates have been working very hard and she believes Republicans could take control of the state Senate for the first time in a dozen years.

“I am betting on our great candidates,” she said. “You always have seats that are open and competitive but you have to have the right candidates running, and I believe we have the right candidates and the right message.”

Weston said there are always surprises in legislative races and that this year is no different. She hopes the surprises this year will benefit the GOP.