Polls show Maine’s northern congressional district — and its one Electoral College vote — is up for grabs in this year’s presidential race between Republican Donald Trump and Democrat Hillary Clinton.

In such tight contests, single issues often are magnified in determining the outcome.

This year, the question of whether President Barack Obama will use his authority to designate a North Woods national monument looms large as that single issue in northern Maine.

Clinton is expected to win handily in the progressive 1st Congressional district, which has voted for Democrats in presidential races since her husband’s election in 1992. But in Maine’s 2nd district, where conservative distrust of the federal government runs deep, the controversial national monument proposal could take on outsize importance, several Maine political observers say.

If the president designates about 87,500 acres donated by Burt’s Bees entrepreneur Roxanne Quimby as a federally protected national monument, northern voters outraged at the prospect of a land grab by presidential decree could turn out for Trump, according to Mark Brewer, a professor and interim department chair of the political science department at the University of Maine.

“That’s a pretty popular stance, being opposed to an overly powerful, meddlesome federal government,” Brewer said. “If Obama steps in to do this, that’s like serving one up to Donald Trump and the Republicans on a tee and saying, ‘crush this.’”

It could assure the Republican billionaire walks away with at least one Electoral College vote in Maine, which awards one of those votes to the popular vote winner in each congressional district. The winner of the statewide vote — polls are pointing to Clinton — collects Maine’s other two Electoral College votes.

So a candidate who loses Maine’s overall vote could still wind up with one Electoral College vote — though Trump would be the first to pull it off.

With polls showing faith in the federal government at an all-time low, Trump is unlikely to resist the opportunity to belt into Obama over a monument designation if the Republican nominee returns to northern Maine. Mike Cuzzi, a political consultant who helped organize the Obama and John Kerry presidential campaigns in Maine, expects Trump, who visited Bangor in late June, will be back.

“I think he will play this issue up very heavily in Maine. If it is made, that’s all you will hear about,” Cuzzi said.

Trump likely will follow Gov. Paul LePage’s lead, he said. The governor “has made some inroads [up north] because he has tapped into some of the economic anxiety there, the way globalization of the economy has changed things,” Cuzzi said.

For Clinton, a monument could serve as a good talking point, as the former first lady and Democratic front-runner furthers her embrace of Obama’s environmental and economic legacy in left-leaning southern Maine, analysts say.

“She has a very aggressive environmental plan that goes far beyond what the president has put in place,” Cuzzi said. “She sees the environment as a winning issue, and the polling bears her out on that.”

If Obama thinks a monument designation could hurt Clinton’s chances, he might hold off on issuing an executive order until after the election, said Corbin Hiar, who covers the monument campaign as a Washington, D.C.-based reporter at Environment & Energy Publishing.

This isn’t the first time the political divide between Maine’s northern and southern districts has boosted the profile of emotional local issues in tight races. A failed referendum to ban bear baiting in 2014 helped to swing 2nd district voters to Republican U.S. Rep. Bruce Po liquin in his contest against Democrat Emily Cain. In 2012, Mainers’ support for same-sex marriage helped Democrats to wrest control of the Legislature back from Republicans.

Southern Maine’s liberal voters support the monument as a progressive fusion of economic and environmental values that will bolster a Katahdin region weakened by mill closures, Cuzzi said.

Their representative, U.S. Rep. Chellie Pingree, favors a monument and supported the national park initiative that preceded it.

“A lot of people in [southern Maine] look up and have a hard time understanding why the Katahdin region is so opposed to this,” Brewer said. “They see this as an economic lifeline and think this would be an economic [boost] to the area, whereas people in the Katahdin region say, ‘You don’t understand traditional land uses, our culture up here. This is just another example of southern Maine telling northern Maine what to do.’”

Poliquin, whose campaign relies on the same political strategist as LePage, Brent Littlefield, has vociferously opposed a national monument.

Yet Northern Mainers aren’t simply conservative, according to Matthew Gagnon, CEO of the Maine Heritage Policy Center, a free market policy think tank based in Portland. Upstate politics are a hybrid of deep conservative dislike of big government and gun control, mixed with liberalism fashioned by decades of involvement in unions, he said.

The northern constituency continues to wait on Obama to determine the future of their region. The president has until the last day of his term in January to designate the Quimby lands as a national monument.

“It’s hard to imagine a bigger issue at least in the Katahdin region, if not northern Maine,” Brewer said.