Billy Walker at his welding job site in Lexington, Va. (Charles Ommanney/The Washington Post)

Every Election Day, as the family story goes, Rodney and Milre Campbell used to turn their general store into the official polling station for the farmers and fiddle players, the loggers and moonshine-makers of Jennings Creek. At day’s end, Milre would conduct the preliminary count by the light of the Delco batteries and maze of wires that Rodney had rigged up — the kind of ingenuity that defined success for the Scots-Irish who’d settled in southwest Virginia.

Not long after the couple married in 1939, recalls their grandson, Billy Walker, all the ballots were for the Democratic candidate for president.

Except one.

“It must be the outsider,” people said. And the only “outsider” was Milre, a woman of Swiss-German descent who had married into the Campbell clan.

Rodney was a “dyed-in-the-wool Democrat,” Walker recalled recently, as was the tradition among the Scots-Irish, who had long said the Democratic Party was there for “the store owner, the logger, the small business.” They shared a heritage with Andrew Jackson, founder of the populist Democratic Party, James Polk and Woodrow Wilson, born just 60 miles away in Staunton, among a dozen or more U.S. presidents. And they were thankful for the New Deal policies that kept many mountain folk from starving.

Which may explain why Milre Balsley Campbell never did admit whether she had cast the rebel Republican vote. She died in 2000.

Today, the Scots-Irish form the cultural core of the white, Southern Republican vote that is being heavily courted by GOP presidential front-runner Donald Trump — and energized by anger at the government and support for conservative stances on guns, abortion and immigration.

Many of these voters, who backed GOP hero Ronald Reagan and then Democrat Bill Clinton, have become reliably Republican.

Democratic candidates, who used to campaign aggressively in the heavily Scots-Irish rural communities of Appalachia, have shifted their attention to liberal whites and ethnic minorities, as Barack Obama did in 2008 and 2012. Now, as she builds her 2016 campaign, Democratic front-runner Hillary Rodham Clinton appears to be focusing on reigniting the Obama coalition. And some state parties are moving away from their Jacksonian roots, dropping the name of the seventh president from annual fundraising dinners because of his support for slavery and his treatment of Native Americans.

Yet some Democrats say the descendants of the Scots-Irish immigrants who arrived in the Shenandoah Valley in the 18th century and are still imbued with their ancestors’ hardscrabble values should remain a target for the party’s eventual presidential nominee — particularly in a battleground state such as Virginia. Census data, which suggests less than 2 percent of the U.S. population identifies as Scots-Irish, fails to reflect their strong historic and societal ties.

“It’s my culture,” said former Virginia senator Jim Webb, who is challenging Clinton for the Democratic nomination and has tried to push his party to fight for Scots-Irish support.

Webb first sounded an alarm in a 2004 Wall Street Journal column in which he credited George W. Bush with tapping into Scots-Irish values and blasted his own party for its ignorance.

“Few key Democrats seem even to know that the Scots-Irish exist, as this culture is so adamantly individualistic that it will never overtly form into one of the many interest groups that dominate Democratic Party politics,” Webb wrote.

He indicated in a recent interview that his frustrations have not gone away: “The Republicans understand them,” he said, faulting his own party for not being “inclusive” enough.

Longtime Democratic strategist Dave “Mudcat” Saunders, a self-described “Scots-Irish hillbilly” who advised Webb and Mark R. Warner in campaigns for Senate and governor, respectively, said Democrats need to refocus on their populist roots, on “Jacksonian democracy, social justice and economic parities.”

However important they are to 2016, rarely does anyone refer to a Scots-Irish vote. They “don’t go for group-identity politics any more than they like to join a union,” writes Webb, whose 2004 book, “Born Fighting,” celebrated the unruly, clannish ancestry that spawned the pioneering (Davy Crockett) and the pugnacious (Hatfields and McCoys) and that Webb has estimated he shares with 10 percent of the population. Instead, the Scots-Irish see their identity — shaped on the scrappy, Calvinist borderlands of England and Scotland, then sharpened on the tenant farms of Ulster — as indistinguishable from the land they made their own with the help of the long rifle and the surveyor’s compass.

“There’s the black vote and the Latino vote, and then there’s our vote,” says Elizabeth Petty, Billy Walker’s aunt and “one of the few” Democrats to live on Jennings Creek today. She’s unsure of her own roots — “It’s a mix,” she says — though her red hair has convinced neighbors that she is of Scots-Irish stock.

“We are just Americans,” she says.

Janie Harris, 57, who describes herself as “independent with conservative leanings” and runs a real estate company in Lexington, rejects the idea that the Scots-Irish can be labeled politically or defined ethnically. Instead, she said, the culture is defined by shared struggles to survive.

“Economically, the people here have always had a struggle,” Harris explains. They got by “by depending on themselves and each other’s good-heartedness,” she said, as she fielded phone calls about a young colleague’s sick mother. There were “no food banks, no government agencies.”

Harris is skeptical of both parties’ leading presidential candidates. She said Clinton is “a very smart woman, but her smartness has equated to shrewdness that’s been off-putting.” Harris described GOP front-runner Donald Trump as “abrasive,” although she said he has “allowed a dialogue to take place that focuses on really key issues.”

“I want a candidate with respect and understanding for working-class people,” Harris said, reaching over to a desk drawer to pull out a photograph of a simple log cabin on property her ancestors settled in the 1700s and that her nephew now owns.

Some scholars say the key to understanding the political culture of the Scots-Irish lies in considering the full scope of their history.

Brandeis historian David Hackett Fischer, whose book “Albion’s Seed” examined the staying power of cultural traditions among early immigrant groups, looks back way before debates about the Confederate flag or the Civil War to the Scots-Irish experience of living on land “that the kings of England and Scotland both claimed, and the result was 1,000 years of warfare.”

That experience, Fischer says, endowed these “borderers” with hardy self-reliance and a “libertarian idea of natural freedom” that plays out in U.S. politics today.

Their history was always to live on the boundaries — and push them. They moved from the Scottish borders to Ireland in the 17th century — Protestant tenant farmers eking out a living between their English landlords and the Irish Catholics. America offered the Scots-Irish land to call their own. More than a quarter of a million migrated across the Atlantic, many to Pennsylvania, where they settled on a border again, between the Indians and the Quakers and established colonists in the east. As their numbers increased, many moved down the Shenandoah Valley, building log cabins in the lowlands, then following waterways such as Jennings Creek into the Appalachian Mountains.

While some, including Harris’s and Walker’s ancestors, staked out territory between the Tidewater, where the Colonial aristocracy held sway, and the wilderness, others left the backcountry for the new frontier, changing the country’s orientation to the South and West and eventually putting their distinctive, anti-authoritarian stamp on states from Kentucky to Colorado and parts of California.

Now, the Scots-Irish may be gaining new cultural currency.

In Northern Ireland, some revivalists have focused on gaining minority-language status for the tongue named “Ullans” — a mix of “Ulster” and the Scots pronunciation “Lallans,” for “lowlands.” There are plans to launch a think tank to increase historical awareness among Americans, including by promoting trips to the Jackson homestead where the former president’s parents lived. Composer John Anderson has written a musical about the early migrants, “On Eagle’s Wing”; it is due to tour the United States in 2017. And tourists who travel through the Shenandoah Valley today find converted mills and farming museums reconstructing the Scots-Irish impact on the country they settled.

Jane Harris’s son Tommy, 27, farms about 750 rocky acres that his grandfather farmed before him, always thinking of ways to leave the land “a little better.”

He wrestles over farming subsidies — whether to accept government money to fence his cattle off erodible slopes, for example, or away from streambeds to prevent their waste from washing down toward the Chesapeake Bay.

“Why should I take a handout and contribute to the problem?” he asks.

He doesn’t feel closely affiliated with either political party and said he wishes there were more choices.

“The tea party tried, but I don’t think they did it the right way,” Harris says. “Their views are too far to the right in many ways and a bit unrealistic.”

None of the current crop of candidates has his full support. “I don’t think [Clinton] could be any less appealing,” he says. And while he appreciates Trump for speaking his mind, Harris doesn’t see him as presidential material. “He says he has a plan, and he doesn’t have a plan.”

The people Harris admires executed plans, sustaining a simple way of life in the wash house, the smokehouse and the distillery that surrounded the farmhouse.

Walker, the Campbells’ grandson, warns against romanticizing a past when people “scraped for every dime.” But the can-do spirit he associates with his heritage continues to animate his decisions.

“People need roots somewhere,” said Walker, 51.

That’s why, after a spell in the military, Walker decided to reconnect with his past.

He rails against the “rules and regulations the government puts on you.” He embraces gun ownership as a “personal decision,” the one that led him to vote Republican.

“I’d rather take some birdshot in the backside than not have the choice,” he said.