But in recent years, the district has tilted leftward as once rural areas of Chesterfield County have been developed into housing that attracts young professionals. The newcomers often have brought different, more liberal political sensibilities, becoming a potent force on gun safety issues. And some suburban women, even longer-term residents of the district like Ms. Johnson, who now considers herself a Democrat, have changed their opinions on gun control or increasingly seen gun limits as central to their political outlook.

In November, that tilt became clear with the election of Ghazala Hashmi, the Democrat who won the State Senate seat with 54 percent of the vote. She defeated Glen Sturtevant Jr., a Republican incumbent who had been endorsed by the National Rifle Association.

“I think women especially have realized they have a strong opportunity to make political change,” Ms. Hashmi said. “For me, I felt not just a deflation of expectation when gun safety laws weren’t passed last summer, but I also noticed there was a more general feeling going around that enough is enough — we’ve given these folks every opportunity to give the public what they want.”

In interviews this week with about two dozen people who live in her Senate district, many said they supported restrictions on firearms to prevent gun violence, including suicides. But opinions varied, often significantly, depending on which portion of the district the voter lived in.

Powhatan County is only a 45-minute drive from Richmond but can feel much further away, with its forested fields and hawks circling overhead. There, people said lawmakers in Richmond had gone too far.

Some said they fear that gun control measures being weighed in the state capital in recent days were a prelude to the government seizing all firearms. “What I see is that people want to control something they’re afraid of, or they don’t understand,” said Jean Gannon, Powhatan County’s Republican Party chairwoman. “This is just the beginning because the ultimate goal is to take guns from people.”

At the root of this district’s — and Virginia’s — political transition is a slow-moving demographic change, a new kind of suburbanization that is sweeping through national politics. From Atlanta to Houston, this pattern is repeating itself — suburban housing developments gobbling up rural areas and farmland and lifting Democrats to power.