It appears likely that ranked-choice voting, being used for the first time in a congressional election, will determine whether Republican Rep. Bruce Poliquin returns for a third term or cedes his 2nd District seat to Democrat Jared Golden of Lewiston.

After one of the most costly and closely watched campaigns in the country, results at 7 a.m. Wednesday, with 72 percent of the precincts reporting, showed a dead heat between Golden and Poliquin with 46 percent each. About 8 percent of the overall vote went to the two independents in the race.

Under the new voting system adopted by Mainers in two statewide ballot questions, the people who voted for independents Tiffany Bond and Will Hoar will have their the second- and third-place choices redistributed to either Poliquin or Golden and the totals will be retabulated until one of the candidates receives at least 50 percent of the vote.

Though Poliquin is generally faring worse than he did in the same towns than he did two years ago, he has history on his side.

No incumbent has lost the 2nd District seat since 1916, when Lewiston lawyer Daniel McGillicuddy fell short in his bid to retain the office in a year that saw Republicans sweep Maine.

Poliquin, the only Republican in New England to hold a congressional seat, has served since 2014, touting the economic insights he gained during 35 years in finance before he entered politics less than a decade ago. CBS and NBC news were projecting that Democrats would re-take the House of Representatives from Republicans.

Golden, a Marine Corps veteran who served combat tours in Iraq and Afghanistan, campaigned on the need for universal health care and more help for working Mainers.

Poliquin said he might challenge the results of the election in court if ranked-choice voting system costs him the election. The other candidates said they would accept the results.

Golden said shortly before the polls closed that he felt calm. He said he did everything he could and is grateful that so many people helped him.

Even the possible demise of his trusty truck didn’t rattle him.

With just a few more hours of the campaign left, Golden’s 2003 GMC Sierra – which he’s used to log more than 50,000 miles along the campaign trail – “just up and died” in Bangor, the candidate said outside Longley Elementary School in Lewiston.

Golden, who got a ride home to Lewiston while his truck was towed away, said the vehicle must have decided “enough’s enough already.” But, he said, he thinks the fuel pump may be the problem so it’s possible the truck has more miles to go before it gives up the ghost entirely.

Golden, 36, spent Election Day bouncing between polling places from Auburn to Rumford to Bangor. Poliquin, 65, focused on the Bangor area during Tuesday’s voting.

Cited by many political gurus as a key swing district that might wind up handing control of the U.S. House to the Democrats after eight years of GOP control, an unusual amount of national attention focused on the outcome of the 2nd District race.

Candidates and political action committees spent more than $18 million during the race, paying for more than 6,400 television commercials — about one every two minutes during the final weeks of the campaign.

Financial disclosure reports showed that Golden raised five times more money than Poliquin in the quarter that ended three weeks before the election. It was the most expensive congressional race in the history of the state.

Because Maine’s television advertising rates are comparatively cheap, dark money super PACs proved eager to pour money into the race. The candidates themselves raised about $9 million, with Golden’s mostly coming from individuals and Poliquin relying on contributions from PACs.

Golden, who raised more money for his campaign than Poliquin did, benefited from about 10 percent more commercials overall.

One of the biggest spenders in the district, the GOP’s Congressional Leadership Fund, spent $3.1 million on ads touting Poliquin or bashing Golden.

Like many other groups on both sides of the aisle, it also paid for a slew of spots on internet sites whose cost is not broken down. Across the country, the Congressional Leadership Fund said it shelled out about $20 million for online ads compared to less than $3 million in 2016, an indication of the growing importance of reaching voters via the internet.

In the 2nd District, the Congressional Leadership Fund also opened a field office in Bangor in March that wound up contacting about 373,000 Maine voters, identifying Republican supporters and trying to make sure they got to the polls in an especially aggressive effort.

Two years ago, Poliquin defeated Democrat Emily Cain by a 55-45 margin, racking up almost 193,000 votes in the process.

In 2014, when he first won the district, Poliquin collected 45 percent of the overall vote, while Cain got 40 percent and an independent, Blaine Richardson, collected 11 percent.

Poliquin, an Oakland resident, got into politics in 2009 when he jumped into the gubernatorial race, losing badly to Paul LePage in the GOP primary. But he went on to become the state treasurer before coming up short in a bid for a U.S. Senate seat in 2012.

His first success at the polls came two years later when he captured a newly open 2nd District seat that Democrats had held for two decades.

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