Mark Holbrook emerged victorious from June’s Republican primary by the narrowest of margins – just 57 votes – in his bid to challenge Rep. Chellie Pingree.

That was arguably the easy part of Holbrook’s campaign in Maine’s 1st Congressional District.

On Tuesday, the psychologist and former police officer will compete for votes against a well-known and well-financed Democratic incumbent in a district that hasn’t sent a Republican to Washington in 20 years. The 1st District race also has been overshadowed by record sums of money dumped into Maine’s heated race for the 2nd Congressional District.

Holbrook often says that he knows he could never compete against Pingree financially, but espouses confidence that voters will rally to his side.

“The strategy is exposing her voting record to the people of Maine,” said Holbrook, who often refers to Pingree as an “ultra liberal.”

For her part, Pingree is once again waging a low-key campaign in a race that most political observers believe she will win handily.

“I believe I have worked hard to represent the district,” Pingree said during a recent debate. “The 1st Congressional District has a very diverse group of residents, from fishermen to farmers, people who live in our urban areas to our rural communities. I have tried to focus on the issues that are most important to us.”

INCUMBENT’S POSITIONS AND GOALS

Pingree, 61, was first elected to Congress in 2008 after eight years in the Maine Senate and three years heading the national progressive group Common Cause.

She supports the Affordable Care Act, but believes universal health care is the preferable option, and was among the Democrats who started a sit-in on the House floor this summer demanding action on gun violence.

Democrats have been unable to achieve their policy objectives in the Republican-controlled House. But Pingree sits on the powerful House Appropriations Committee, giving her a voice in funding for agricultural, natural resources and rural economic development issues.

“It is not fun every day (in Washington), but I feel fortunate with my committee assignments,” Pingree said. “We do a lot of work here in Maine, helping people with their Social Security benefits, challenges they have with student loans. … There is still an enormous amount of things we get to do even when Congress is deadlocked.”

Pingree also has been a prominent voice on policies aimed at supporting smaller-scale agriculture and farmers markets.

She’s won her two last elections with more than 60 percent of the vote and has run a low-key campaign this year. The last blog entry on her “Chellie Pingree for Congress” website, for instance, is from February 2015, and many of the posts on her campaign’s Facebook page pertain to her support of Hillary Clinton or opposition to Donald Trump.

Holbrook often portrays Pingree as being “missing in action” in Washington while accusing the congresswoman of focusing on the wrong issues for 1st District residents.

“She isolates herself on an island,” Holbrook said, a reference to Pingree’s home on North Haven, where she has operated an inn and restaurant as well as an organic farm. “She gets on a plane in Rockland, flies to Portland and then gets on a plane to Washington.”

CHALLENGER RUNNING AS OUTSIDER

A licensed counselor, Holbrook works with law enforcement officers as well as veterans and families at his Brunswick practice. He spent more than a decade in law enforcement in addition to previous work as a lobsterman and an instructor on hostage negotiations. Running as an outsider, Holbrook often rails against “the ruling class in Washington” – a derogatory grouping he said includes some national Republican leaders.

“I look at the establishment and what they are doing, and it’s all wrong,” Holbrook said. “We can’t trust them. … We sent what we thought were conservative Republicans to stand up to Barack Obama and they haven’t done it.”

Yet Holbrook’s hard-right positions are unlikely to resonate with many moderate or left-leaning voters in a district that hasn’t had a Republican representative since 1996.

He supports building a wall or fence along the U.S. border with Mexico and considers border insecurity the nation’s top national security threat. He has called refugees from war-torn countries “a potential Trojan horse” for terrorists and argues that political correctness is stifling America.

“Our religious freedom is under attack and they want to take our guns away under the false pretense of reducing violence,” he said.

Holbrook prevailed over his more moderate primary opponent, Ande Smith, by just 57 votes after a recount.

Brian Duff, associate professor of the political science program at the University of New England, sees Holbrook’s conservative candidacy through the prism of what is happening to the Republican Party.

Duff said Holbrook seems to be offering the “Paul LePage-Donald Trump version of America” with his “angry, law-and-order message.” And Duff noted that this is happening at a time when moderate Republicans, such as Maine Sen. Susan Collins, are largely staying on the sidelines.

“The Republican voice you hear loud and clear more often than any other (in Maine) is Paul LePage,” Duff said of Maine’s outspoken and proudly politically incorrect governor. “And with Holbrook, you can tell he has picked up some of his messages from Paul LePage and Trump.”

FUNDRAISING, NAME RECOGNITION

Those messages could deliver Trump one electoral vote from Maine’s more conservative, blue-collar 2nd District. It will be a harder sell for Holbrook in southern Maine, however.

A mid-October survey for the Portland Press Herald showed Pingree leading Holbrook by 59 percent to 24 percent among roughly 300 likely voters, with 13 percent still undecided. A September poll had Pingree at 64 percent and Holbrook at 22 percent.

When asked about the candidates’ favorability, 78 percent in the October poll said they did not know Holbrook well enough to have an opinion. Pingree was viewed favorably by 52 percent of participants.

Holbrook had raised just shy of $100,000 for his campaign and had $11,000 in “cash on hand” as of Oct. 19, compared with $547,000 still sitting in Pingree’s campaign account.

The Republican challenger recently spent $27,000 to air 61 television commercials through Election Day, while Pingree has yet to reserve any television airtime, according to the most recent federal filings.

By contrast, more than 9,300 ads had been aired as of mid-October in Maine’s 2nd Congressional District by candidates Republican Rep. Bruce Poliquin and Democrat Emily Cain, or by national groups. That is more than any House race nationwide, according to the Wesleyan Media Project.

AGREED: ELECTION VERY IMPORTANT

With limited cash for widespread advertising, Holbrook has relied on debates, forums and community events throughout the district. At an October meet-and-greet at an American Legion hall in Bath, Holbrook ate pizza and chatted with the handful of voters about his campaign priorities, the six ballot questions and, inevitably, the presidential race.

The Republican described the 2016 elections – particularly at the presidential level – as the most important of his lifetime. Asked what would prevent him from becoming the type of Washington politician he so often criticizes, Holbrook replied that he has “a very stiff spine.”

“I couldn’t go to Washington and vote for some (issue) knowing that violates what my values are,” he said.

Pingree sees the 2016 elections in a similar light, albeit from the other side of the political spectrum.

“Almost everyone I know says, ‘Please get this election over with,’ ” Pingree said. “But I think after this election, who represents us in Congress, in the United States Senate and who is in the White House is going to be very important.”