Jon Ossoff, the Democratic candidate for Georgia’s 6th Congressional District, campaigns at a restaurant in Tucker, Ga., on Thursday. (Erik S. Lesser/EPA)

As the most expensive House race in history heads into its final full week, there is one name that is rarely mentioned by the two people who are running.

But President Trump looms over everything.

As Democratic candidate Jon Ossoff was making his way through a retirement community here on a recent weekday, a woman named B.J. Mix gripped his hand and told him: “When you get there, give Trump hell.”

Later that afternoon, in Republican contender Karen Handel’s home precinct in Roswell, Dominick Scartz opened his front door to the latest in a parade of election canvassers to show up on his porch.

“The Republicans don’t want to lose a seat and start a trend,” Scartz said. “But Trump gives everybody an opening. We all know that, even though we voted for him.”

Karen Handel, the Republican candidate for the 6th Congressional District, speaks during a campaign fundraiser at the Cobb Energy Performing Arts Centre in Atlanta on Friday. (David Goldman/AP)

Under normal circumstances, this special election to replace Health and Human Services Secretary Tom Price in Congress should not even be competitive. Once represented by House Speaker Newt Gingrich, the affluent district on the northern outskirts of Atlanta has been in Republican hands for nearly four decades.

Even more unlikely is the situation today: Political newcomer Ossoff, a 30-year-old former congressional staffer and documentary filmmaker, nearly won outright a 16-candidate primary April 18. Now, he is locked in a runoff with former secretary of state Handel, 55, the June 20 outcome of which is anyone’s guess.

A poll published Friday by the Atlanta Journal-Constitution showed Ossoff with a seven-point lead, but other recent surveys suggest a dead heat.

The closeness of the contest in the 6th Congressional District reflects, to some extent, the changing demographics of this fast-growing area, which Trump barely won over Hillary Clinton in last year’s presidential election.

But what is really driving things is a national proxy battle between energized Democratic forces on the left and a GOP mobilized by fear of what may be to come in next year’s midterm battle for control of Congress.

Special elections earlier this year in Kansas and Montana have already revved up Democrats in ruby-red districts; Georgia’s is a contest they might win. After several near-misses, it’s also a race they must win to demonstrate that Trump is the liability they say he is — and to make progress toward their goal of winning a House majority in 2018.

(Bastien Inzaurralde/The Washington Post)

It is an arms race of money and organization. The latest fundraising report, filed Thursday, showed Ossoff raising an additional $15 million in the past two months, nearly quadruple what Handel brought in. With outside groups weighing in, the race has thus far cost more than $40 million — far outpacing the previous record for a congressional race of nearly $30 million for a Florida contest in 2012.

Polls indicate there are few voters still undecided. “The next 10 days are about turning out the base. There are more of us than them in the district. The more people who vote, the better,” said Corry Bliss, who heads the Congressional Leadership Fund, a super PAC affiliated with House Speaker Paul D. Ryan (R-Wis.). That organization alone plans to spend about $7 million in the race.

Another factor, however, may be working in the Democrats’ favor: After a federal judge ordered that voter registration be reopened for the runoff, more than 8,000 were added to the rolls in the 6th District.

And in the first round of voting, Ossoff won what analysts on both sides believe to have been at least 10 percent of voters who generally cast their ballots for Republicans. (Georgia does not identify voters by party.)

Early voting suggests that turnout will indeed reach new heights, at least for a special election. Both sides are closely analyzing the numbers, which indicate more Republican votes than normal in early voting, though it is unclear how much of that is driven by sheer fatigue with the bombardment of ads and phone calls and a desire to just get the whole thing over with.

So saturated is television that one local station has temporarily replaced reruns of “The Andy Griffith Show” with a 7 p.m. newscast, just to accommodate the demand for slots to spend ad dollars.

There are some who now deem the subject off-limits. “I don’t talk to people about the race, quite frankly,” said Eric Clarkson, mayor of Chamblee, a town that Ossoff won easily in the first round of voting.

For others, however, this election represents a political awakening.

Nadine Becker, a gynecologist, had never even gone on Facebook. Now, three times a week, she spends several hours volunteering for Ossoff.

“After November, I pretty much came alive with regard to politics. The fact is, here in the 6th, we have something to do,” she said. “It’s Trump, but it’s more for the first time in my life, I feel that things that I value, that are important to me, have been threatened.”

Neither of the candidates is particularly dynamic. Both stick closely to their talking points, and Handel in particular has few publicly announced events.

In their two debates last week, Ossoff was the more polished.

During the first one, while discussing her opposition to raising the minimum wage, Handel committed a gaffe with her pronouncement: “I do not support a livable wage.”

Pressed during the second debate on whether she believes human activity is a cause of climate change, Handel demurred, saying: “I am not a scientist.”

Ossoff shot back: “Well, neither of us are scientists. That’s why we have scientists. And 97 percent of scientists, as well as the military and the intelligence community, agree that climate change is a threat to our security and prosperity and that it’s driven in part by human activity.”

But Trump’s presence looms over both of them.

After Handel made it to the runoff, Trump came to Atlanta to raise $750,000 for her. “You better win,” he told her.

With the appointment of a special counsel to investigate the questions surrounding Trump and Russian interference in the 2016 election, Handel has said she wants to “let the facts really drive where we go and what action we take.”

She also allowed that she wishes Trump would make “some Twitter policy changes. Sometimes you should just put down the computer, the phone, and walk away.”

Ossoff said Russia’s actions merit a “firm response and a transparent, independent investigation” but added that “we’re still not there yet” on the question of whether Trump should be impeached.

Handel insisted Trump should not be the main issue for voters.

“This race is not about the president. It is about who is most equipped and has the best experience,” Handel said during a debate Thursday. “I am not an extension of the White House. I am an extension of the people of the 6th District.”

That doesn’t stop Handel from constantly arguing that Ossoff would be a puppet of House Minority Leader Nancy Pelosi (D-Calif.) — whose name Handel invoked more than 10 times during a debate two days earlier. Pelosi is also featured prominently in ads that are running against the Democrat.

While Ossoff used to describe himself during the primary as the “make Trump furious” candidate, he now talks about finding bipartisan solutions on issues such as health care, and emphasizes cutting federal spending and “independent-minded leadership.”

When Ossoff declined to participate in a nationally televised debate on CNN, Republicans said it was to avoid letting his fan base of liberal funders across the country hear the moderate message he is sounding in the district.

He frequently reminds voters of Handel’s past role as a top official at Susan G. Komen, the breast-cancer research foundation, during the controversy over the charity’s 2012 decision, quickly reversed, to eliminate grants to Planned Parenthood for breast-cancer screening and education programs.

In addition to the fact that he has drawn so much support from out-of-state liberals, Ossoff’s own greatest vulnerability may be his youth, and lack of experience. One Congressional Leadership Fund attack ad features an old video of Ossoff as a college student dressed up as the “Star Wars” character Han Solo. Ossoff also lives just outside the district lines, though he has said he plans to move there.

“He’s just a sham. He’s nothing. He’s got no experience,” said Scartz, the voter interviewed at his front door in Roswell.

That was pretty much the same thing many were saying last year, when a real estate mogul with no background in government was on the ballot for the highest office in the land.

Trump won because voters were looking for an antidote to what they saw as wrong in Washington. Now, the question being tested in Georgia by another political newcomer is whether Democrats have found their antidote to the antidote.