Rep. Barbara Comstock (R-Va.), right, greets Korean Americans at the annual Korean Bell Ceremony at Meadowlark Gardens in Vienna. (Bill O'Leary/The Washington Post) (Bill O'Leary/Washington Post)

Barbara Comstock doesn’t act like a member of Congress who just easily won her first election; she acts like she’s already in a tough race for the next one.

On Saturday, she was out at 5 a.m. to greet a search-and-rescue team returning to Fairfax County from Nepal. Later she would head to a festival in McLean and attend a gala for brain-tumor research. But first, there was the annual Korean Bell Ceremony in Vienna, where she cooed at little girls in hanbok and said “kam sa mi da” — thank you — to the crowd.

Democrats, meanwhile, blast out e-mails on her every vote, calling her “perilously out of touch.” While Comstock says she’s focused on her work in Congress, she’s also sending out fundraising appeals, in which son Peter describes his mom as “on the top of the Democrat hit list.”

There’s reason for her to be there, even though she won last fall by 16 points — and doesn’t even have an opponent yet in next year’s election.

“The race for Barbara has always been about 2016; it was never about 2014,” said Dan Scandling, a longtime aide to Comstock’s predecessor, Republican Frank R. Wolf.

The district Comstock represents is notoriously independent, swinging back and forth in the past few elections. Republicans have only a slight edge, and in a hotly contested presidential race, Democrats can overcome it.

Turnout in midterm elections favors Republicans; in a presidential year, Democrats do better. Virginia will be a key battleground for both parties next year. Hillary Rodham Clinton, the leading contender for the Democratic nomination, is already recruiting volunteers in the state. She also has assembled a campaign team with many ties to the commonwealth.

Along with the presidential race, Democrats hope that an intense effort in this year’s state legislative elections will draw out new voters in Loudoun and Prince William counties. Two Republicans are retiring in Democratic-leaning state House districts in the area; so is a longtime Democratic state senator.

“We have many competitive races that touch what is now the 10th District that will give whoever runs in the future . . . a great leg up,” said Brian Zuzenak, who runs Gov. Terry McAuliffe’s political action committee.

If 2016 is a better opportunity for Democrats, it might also be their last unless future redistricting changes the lines. The longer Comstock spends in office, the stronger her ties will grow to a district that values constituent service over partisan identification.

If we don’t unseat her this cycle, “she’ll start to burrow under the skin,” said one Democratic operative.

Virginia’s 10th District, which stretches from the rural, conservative Shenandoah Valley through Loudoun and the edge of more liberal Fairfax, is one of the most evenly divided in the nation. Federal workers and contractors made up a large proportion of the population; so do immigrants. In 2008, voters there narrowly supported President Obama; four years later they supported Mitt Romney.

Comstock is following the model that made Wolf impossible for Democrats to unseat despite an increasingly amenable electorate. On pay for federal employees and funding for regional transportation, she has bucked her party. She voted against all three Republican budget proposals earlier this year, saying they were too cruel to federal workers. This past week, after riding the train with Obama’s transportation secretary, she rebuked GOP leaders for trying to cut Metrorail funding. Asked in a recent interview about Clinton, she demurred that “it’s always good to stay in my lane.”

Democrats counter that Comstock far more often votes with Republicans, including this week for a late-term abortion ban and against allowing young illegal immigrants to serve in the armed forces. She’s hypocritical, they say, for lamenting Metrorail cuts when she opposed a major transportation funding bill while serving in the Virginia House of Delegates in 2013.

“Barbara Comstock is as political as they come, so it’s no surprise she’s trying to push a faux-moderate image with a few photo-op moments,” said Morgan Finkelstein, a spokeswoman for the Democratic Party of Virginia.

Comstock says she never opposed the Metro funding in that legislation — just the tax burden on Northern Virginia.

Wolf was just as conservative on abortion and immigration. His appeal lay in his clout and commitment when it came to regional concerns. A savvy and inexhaustible campaigner, Comstock is trying to cultivate the same loyalty, even though she lacks the seniority her predecessor held.

“We see her at every event you can think of; she’s at community events, she’s at fundraisers,” said Virginia Republican Party Chairman John Whitbeck, who lives in Comstock’s district. While he conceded that “in a presidential year the turnout is always going to be difficult,” he said Democrats would struggle to find a candidate as formidable.

“They don’t have a deep bench in Loudoun; they haven’t had a deep bench in a long time — so I don’t see them having anyone near as impressive as Barbara Comstock,” he said.

Several Democrats have named two possible recruits they see as strong: Shenandoah University professor Karen Schultz, who came close to winning an expensive state Senate race in 2007, and Cate Wyatt, a former state secretary of commerce who now works on historic preservation. Also mentioned are state Sen. Jennifer T. Wexton and state Rep. Kathleen Murphy, though both say they are focused on winning reelection this fall.

Comstock is on the National Republican Congressional Committee’s list of vulnerable incumbents already receiving organizational and fundraising support. She raised about $400,000 in the first three months of 2015 — plenty for an incumbent with no immediate challenger.

Democrats had hoped for a competitive race in this narrowly Republican district in 2014, when Wolf retired after three decades in office. Instead, they suffered a disastrous loss.

Both sides say that Fairfax County Supervisor John W. Foust was mortally wounded by a clumsy comment he made a few months before the election. Speaking to supporters, he mused that Comstock had never had a “real job.” Having failed to define himself in voters’ minds, he became known only for an insult many women saw as sexist. Additionally, Democratic Sen. Mark R. Warner’s unexpectedly narrow victory offered no coattails on which to cling.

It was a missed opportunity for Democrats, but it was also just the first round.

Correction: An earlier version of this story incorrectly said Comstock would host a campaign fundraiser for a state Senate candidate on Saturday.