PORTLAND – Sheila Dobrowolski planned to be one of the first in line at her polling place, at 7 a.m. Tuesday.

“My motto is, if you don’t vote, don’t complain,” said Dobrowolski, a 51-year-old Democrat from Portland.

Ouda Baxter, 24, couldn’t even wait for Election Day. She cast her ballot at Portland City Hall on Friday.

“There’s a lot at stake,” said Baxter, an independent.

Polling places will be open across the state until 8 p.m. Tuesday, and voters are energized and eager to have their say on the issues, from the national to the local.

Interest is especially high in Maine’s unpredictable referendum on legalizing same-sex marriage and in the intense race for president, according to polls and interviews with voters.

For Baxter and Dobrowolski, helping to pass the marriage proposal is the biggest reason to vote in this election.

“That’s huge,” Baxter said of the referendum.

“I have two very good friends who should have that right,” said Dobrowolski.

Andrea Leblanc, 58, a Republican in Topsham, said she feels most strongly about the presidential race, and plans to vote for Republican Mitt Romney.

She said the marriage referendum also is important to her. She plans to vote “no.”

“I do not agree that they need to change the definition of marriage,” Leblanc said.

The outcome of the same-sex marriage referendum — Question 1 on the ballot — remains tricky to forecast. Polls have consistently shown supporters leading opponents, but the gap narrowed in the latest round of polls, and experts say the final vote is sure to be close.

Even though President Obama is expected to win Maine, the uncertain outcome nationwide has Maine voters eager to cast their votes.

In a poll conducted for the Portland Press Herald by Critical Insights last week, 87 percent of likely voters said they have followed the presidential race closely and 73 percent said they have given a lot of thought to the same-sex marriage debate.

Sixty-one percent of voters said they have closely followed Maine’s U.S. Senate race, and 44 percent said they have thought a lot about the two races for U.S. House of Representatives.

“I’m not that concerned about the (U.S. Senate race). I’m confident Angus King is going to win, and I support him,” said Ben Leoni, 30, an attorney who lives in Portland and plans to register at the polls. “The bigger cliff-hangers are the presidential race and Question 1. I’m very concerned about those. … I definitely want to make sure I’m there to vote.”

Leoni said he supports Obama and same-sex marriage.

Chris “Benji” Levine, 24, who operates a hot dog stand in Portland, said he favors Romney over Obama. But he is most concerned about making sure the same-sex marriage proposal passes.

“Question 1 is really the only one I actually care about,” he said.

Towns and cities open their polls at various times, although the state requires that all polls be open by 10 a.m. Polls close at 8 p.m. statewide.

Election officials say they expect turnout of 70 percent to 80 percent or more, which means big crowds at the polls during peak voting times.

Maine typically has turnouts of more than 70 percent — about 700,000 voters — in presidential election years.

“You’ll see a decent turnout, especially with Question 1,” said Biddeford City Clerk Carmen Morris. “That will bring people out.”

South Portland City Clerk Susan Mooney said she is preparing for a turnout of more than 80 percent, in part because her office has been busy registering new voters. “We’ve had lot of people come in today,” she said Monday afternoon.

Maine residents can register to vote at the polls on Election Day, although Mooney encouraged people to come in ahead of time because of the anticipated turnout. “We typically have long lines at the registrar’s table” on Election Day, Mooney said.

Nicole Mokeme of South Portland beat the rush by going to City Hall to register Monday. The 26-year-old mother and nanny said she is most concerned about health care and education, and plans to vote for Obama.

One issue that voters of all stripes appeared to agree on Monday was relief that Election Day has arrived and political advertisements are about to go away.

“I don’t even watch TV because it’s, like, overwhelming,” said Ouda Baxter.

Staff Writer John Richardson can be contacted at 791-6324 or at:

jrichardson@pressherald.com