Rep. Barbara Comstock (R-Va.), left, greets Korean Americans in the Korean Bell Garden at the Meadowlark Botanical Gardens in Vienna, Va., in May 2015. (Bill O’Leary/Washington Post)

At a drug-awareness rally in the rural swath of her Northern Virginia district, Rep. Barbara Comstock clasped hands with a recovering heroin addict as if they were old friends.

She suggested treatment options to teary moms and cooed over pictures of a caseworker’s kids. As the park cleared out, she stayed to chat with a doctor treating three-pound babies born hooked on opioids.

“It’s nice to see her out in the community,” said James Thall, 41, a recovering addict. “Just talking to her, she seems like she really cares.”

If Comstock (R) can overcome the anchor of the Donald Trump candidacy in her swing district, this is how she’ll do it. With a focus bordering on obsession, the freshman congresswoman puts a premium on constituent services and has ingratiated herself with every rotary club, fire company and charity that will have her.

But it could still be close.

LuAnn Bennett, Democratic House candidate in Virginia's 10th district, speaks with Heidi Zollol in Herndon, Va., March 1, 2016. (CQ Roll Call via AP Images) (Al Drago/AP)

Comstock faces a vigorous challenge from LuAnn Bennett, a first-time candidate but longtime Democratic donor who is trying her hardest to yoke Comstock to Trump. The nonpartisan Cook Political Report has changed its prediction of the race from “likely Republican” to “lean Republican,” signaling a more competitive race.

Although drawn five years ago to favor a Republican, Virginia’s 10th Congressional District includes all of Loudoun County, the richest county in the United States and a suburban commuter haven that occasionally tilts blue thanks to an influx of educated professionals, many of them minorities and women.

Loudoun voters made history last November when they elected Phyllis Randall, a Democrat, to become the first African American woman to chair a Virginia county’s board of supervisors.

These voters are cool to Trump’s comments that Hillary Clinton “doesn’t have that strength and stamina” to be president, his calls to deport illegal immigrants and plans to build a wall at the U.S. border with Mexico. Although Trump carried the state in the GOP presidential primary, he was beaten badly by Sen. Marco Rubio (R-Fla.) in Comstock’s district.

Comstock has not endorsed Trump and still sports a Rubio bumper sticker on her car. Cautious to the point of inspiring opponents to dub her “No Comment Comstock,” she has steered clear of anything Trump, hoping voters stick by her even if they can’t vote for the top of her ticket.

Will she endorse him before the election?

“If I change my mind, I’ll let you know,” she said in an interview.

Is she going to vote for him?

“I’m watching.”

Bennett says Comstock’s attempt to distance herself from Trump belies their shared agenda.

Both Comstock and Trump want to overturn Roe v. Wade, oppose measures that would close the wage gap between men and women and hold extreme views on immigration, Bennett says.

Democrats have also linked the congresswoman to Trump through his campaign manager, Kellyanne Conway, and her deputy, David N. Bossie, who have worked with Comstock in GOP politics over the years.

A Georgetown-educated lawyer, Comstock, 57, was working for her predecessor, longtime congressman Frank Wolf, in the 1990s when a constituent complaint grew into Travelgate, a probe into what Republicans said was a plot devised by Hillary Clinton to replace seven staffers in the White House travel office with Clinton friends.

From there, Comstock built a reputation as an uber-prepared chief counsel on the House Oversight and Government Reform Committee and opposition researcher for the Republican National Committee. She won election to Congress in 2014 with 57 percent of the vote.

Comstock said she is committed to issues important to her constituents, including national security, Metro funding and the opioid crisis.

“Voters here are independent, and they look at people based on who they are,” she said. “People have seen me in their community, at their local events, at their local schools, at their businesses where I visit every week. I’ve worked very meticulously with them on a whole host of issues that are priorities.”

She argues that it’s important to have a Republican representative in the GOP-controlled House, noting that as a member of the House Transportation and Infrastructure Committee she helped push to get $5.4 billion in formula funds for Virginia’s highways inserted into a five-year transportation law.

Bennett, 62, has emphasized her background as a real estate executive and single mom. She owns the Bennett Group, a real estate development and management firm she started in the 1980s with her first husband, Richard, who died of leukemia. She is divorced from James P. Moran, the former Democratic congressman from a neighboring district.

A prolific political donor, she gave about $113,500 to Democratic candidates and causes in the past decade, according to the nonpartisan Center for Responsive Politics.

Bennett has shown some shakiness on the campaign trail and made a few missteps in an otherwise strong campaign, political observers say.

“She has a lot of mettle,” said state Sen. Barbara A. Favola (D-Arlington), referring to the way Bennett built a business and raised her children as a widow. “A very savvy businesswoman. It took some doing when she was going along. It was harder to get loans from banks. She didn’t have a lot of experience and here she is, the CEO of this company.”

“She’s a salt-of-the-earth, no-nonsense, get-the-job-done person centered on family values,” Favola said.

Bennett said she will champion women’s issues in Congress, focusing on equal pay, paid family leave and health care.

But she failed to win the Virginia AFL-CIO endorsement and, with it, labor’s voter-turnout engine. It marked the first time in a decade that the union declined to endorse a Democrat running in the 10th District.

She has also lagged in the money race, raising $1.2 million to Comstock’s $3.2 million, as of June 30.

A relative unknown, Bennett has outspent Comstock on television advertising so far, running spots to introduce herself to voters.

Both candidates are counting on a boost from national groups. Republicans have reserved about $5 million to help Comstock compared with about $2.6 million for Bennett from Democrats.

On a recent campaign stop, Bennett waded through swarms of people at a festival at the Eden Center, a Vietnamese strip mall. It was an unlikely venue — the Falls Church center is outside the district, and many of the people approached by Bennett lived in Maryland or elsewhere in Virginia.

In search of a connection, Bennett dropped Clinton’s name. “I really support Hillary Clinton’s small-business plan that aims to make starting a small business easier,” she said.

Later, at the Haymarket Day Festival in Prince William County, Bennett greeted voters among the funnel-cake and corn-dog booths. She skipped the popular parade earlier in the day, missing a chance to show voters how she compares with Comstock, who was there.

Still, she got some support. Chalet Jean-Baptiste of Gainesville, 36, an English professor at Northern Virginia Community College, recognized Bennett and hugged her.

“I’m hoping you beat Barbara Comstock,” she said. “We’ve got to.”

Jean-Baptiste said she suspects Comstock is a closet Trump supporter because she won’t say for whom she plans to vote. “If you can’t answer that question, then I don’t believe you,” she said.

Bennett is counting on voters such as Jean-Baptiste and points out that Comstock and Trump align on several issues.

Comstock twice blocked consideration of the Paycheck Fairness Act, which would have made it illegal for employers to retaliate against a worker who discloses their pay or the pay of others in an inquiry.

She voted repeatedly with her caucus to defund Planned Parenthood and supported a bill that would ban abortions after 20 weeks of pregnancy; it was later blocked by the Senate.

Comstock said she voted to avoid a government shutdown in the interest of national security — and to keep an investigation running into covert videos of Planned Parenthood employees. No wrongdoing was uncovered.

Meanwhile, Comstock has painted Bennett as an interloper unfamiliar with the needs of the district who would blindly support Clinton.

In a district flush with federal workers, Comstock earned a 60 percent rating from the National Active and Retired Federal Employees Association, easily surpassing other Republican members of Congress.

Comstock says Bennett would cut military budgets, citing an endorsement the Democrat received from the Council for a Livable World, which said Bennett “believes that U.S. Pentagon spending is too high.”

Bennett said all agencies can more efficiently spend taxpayer dollars and accused her rival of selectively highlighting her positions.

Comstock and Republicans also question Bennett’s residency. They claim she lived in her Ritz-Carlton apartment in Washington, near her office, rather than her Delaplane, Va., farm 55 miles away, before she jumped into the race, to avoid the District’s higher tax rate.

“Since she hasn’t lived in this district for most of the past decade, she’s really not familiar with the issues or the priorities of the district,” Comstock said.

Bennett said she has lived in Virginia for 35 years and spent only “a night or two” in Washington, preferring to commute to Virginia.

“I listened to a lot of books on tape,” she said, adding, “The residency issue for Barbara is like Donald Trump’s birther issue. It’s a red herring. It’s a distraction.”

It may not matter.

Comstock is popular in the conservative western parts of the district, where her message of faith and family resonates, but also among the wealthy business crowd.

Nearing the end of a long day, she ducked into a McDonald’s and changed into a black suit to attend a gala at a therapeutic equestrian center in Loudoun. At the end of an unpaved road, the party was in full swing in a stable dotted with crystal chandeliers and white lights.

It was after 10 p.m. when she finally left.

At a police appreciation dinner earlier that night in Clarke County, she worked the room, telling the gathering she is trying to secure federal funds to combat heroin coming from Baltimore.

On her way out, a woman emerged from the kitchen to seek help for volunteer firefighters who experience respiratory issues on the job.

“Okay, well, let’s figure out whether it’s county, state, federal,” Comstock said. “We’d be happy to look into it.”

Correction: An earlier version of this story misstated the rating that Rep. Barbara Comstock received from the National Active and Retired Federal Employees Association. She received a rating of 60 percent, not 66 percent.