RICHMOND, Va. — If there is going to be a wave sweeping House Democrats into power in Tuesday's midterm elections, political experts say the results in Virginia’s 7th Congressional District could be one of the earliest indicators.

Solidly Republican since the days of Richard Nixon, the district — north and west of the state capital — is now a toss-up, according to recent polls.

The race pits incumbent Republican Rep. Dave Brat against Democrat Abigail Spanberger, a former CIA undercover operative and first-time candidate. Brat, who ousted House Majority Leader Eric Cantor in a 2014 primary upset by using anti-immigration attacks, was an early adopter of the brand of identity politics that now define the GOP in the Trump era.

Spanberger, who began her career as a federal law enforcement officer working narcotics and money laundering cases, is emphasizing her national security credentials and vowing to focus on health care and prescription drug costs, student loan debt and modern infrastructure.

She may also become part of a “pink wave” of women who have laced up their running shoes after President Donald Trump’s election.

“In 2016, as we saw some of the rhetoric increase and we saw the division in our community, the divides, for me it was an incredibly motivating time because there are so many challenges facing our country,” Spanberger told supporters at a luncheon last Thursday in Louisa, northwest of Richmond.

The race is seen as a bellwether for whether college-educated suburban voters — especially “Panera moms” who traditionally vote Republican — will repudiate Trump and his brand of politics by voting Democratic or staying home.

David Wasserman, House race analyst for the Cook Political Report, says it will be among the first races he’ll be watching on election night, with polls closing in the state at 7 p.m. EST.

“It’s a good early test of how far the ‘suburban revolt’ will take Democrats,” said Wasserman.

Sen. Tim Kaine, D-Va., who campaigned with Spanberger this week, told NBC News: “I want a wave of compassion and decency in this country. If there's going to be that kind of wave, the people all over the country and the world want to see, I think Virginia will be the start of it.”

Three forces need to converge to push Spanberger over the finish line, said Quentin Kidd, dean of Christopher Newport University's College of Social Sciences in Virginia.

The first is Democratic women who’ve been organizing for two years. “I give them credit for putting this race where it is,” said Kidd, referring to the Liberal Women of Chesterfield County, which began organizing two days after the 2016 election.

The second is Brat’s personal profile. “He’s operated really like Trump has. He cares only about his base,” said Kidd.

And finally, there are the “Cantor Republicans,” especially women in suburban Richmond who voted for Brat’s predecessor and are now turned off by Trump. “They are pushing this to being a tied race,” he said.

The Woman Factor

A poll released last Monday by Christopher Newport University showed the race statistically tied, with 46 percent of likely voters favoring Spanberger and 45 percent supporting Brat. That’s a significant shift from two years ago, when Brat beat Democrat Eileen Bedell by 15 points.

The poll found a gender gap in the 7th, comparable to other districts across the country, with men favoring Brat by 13 points, and Spanberger leading among women by 16 points.

In interviews, longtime Republican voters said Trump’s focus on culturally divisive issues is driving them further from the party.

“I would feel a greater sense of loyalty to the Republican Party if anyone would break ranks and have the strength of character to say ‘I really will not tolerate this in our country,’” said Sarah Vogt, a Republican who worked in the George H.W. Bush administration.

And some GOP men planning to support Spanberger also cited cultural division as well as national security concerns for their decision. Mike Walworth, who previously supported Brat, said GOP attacks on special counsel Robert Mueller and his investigation of Trump’s ties to Russia was “the first straw.” Said Walworth, “It is a national tragedy what they are trying to do to Bob Mueller.”

Democratic enthusiasm and activism is adding to the mix.

Two days after Hillary Clinton’s loss to Trump, Kim Wright, 47, a stay-at-home mother of three, founded the Liberal Women of Chesterfield County in a once-reliable Republican stronghold that is now an epicenter for potential swing votes.

“The election happened and it became a full-time job for me to be dealing with all of this,” she said. The group now has more than 3,600 members who have been instrumental in organizing grassroots actions including canvassing and organizing candidate forums.

The group’s first target was the 2017 gubernatorial election. Trump carried Chesterfield, a traditionally Republican neighborhood, by about 4,000 votes in 2016. But Gov. Ralph Northam carried it last year, the first time a Democrat did so since 1961.

“Trump is the original sin. That’s who got these women energized and mobilized in the beginning," Kidd said. "Those women started this. Trump ultimately is the headwind for Brat."

Wright’s members have been so disciplined about showing up at Brat’s public events that he just stopped doing them, according to Kidd. “The women are in my grill no matter where I go,” Brat lamented in January 2017 — an observation that may foreshadow his fate on Tuesday.

More than many other GOP incumbents, Brat is a reflection of Trump’s politics. He emphasizes border security, crime, the military and protecting gun laws in his platform.

On Oct. 18, Trump issued an endorsement on Twitter, saying Brat “is a powerful vote for MAGA and loves the Great State of Virginia. Dave has my Total Endorsement!”

Rep. Dave Brat, R-Va., greets supporters after a debate with Democratic challenger Abigail Spanberger at Germanna Community College in Culpeper, Virginia, on Oct. 15, 2018. Steve Helber / AP file

Brat is also one of a handful of candidates in Congress who received contributions in 2018 from the U.S. Immigration Reform PAC, whose president is the spouse of “the architect of the modern day anti-immigrant movement in the United States,” according to the Anti-Defamation League.

The PAC has a history of contributing to right-wing nationalist candidates. The other recipients include Mo Brooks, who has said Democrats are waging a “war on whites” and called for mass deportation.

Kidd, the social science professor, emphasized the race is truly up in the air on Tuesday night.

Voter registration in Chesterfield this year is double what it was in 2014, and the number of people who have already voted absentee is nearing double the number that year, according to the registrar's office.

“They’re not getting picked up in our samples because we’re drawing samples based on past voting behavior,” he said.