Voters in Virginia’s largest jurisdiction on Tuesday reelected all eight incumbents on the county Board of Supervisors, including Chairman Sharon Bulova, and chose Democrats to fill two open seats.

After bitter campaign disputes over the county budget, taxes, traffic and even a gun store in affluent McLean, the election provided a strong endorsement of the status quo in Fairfax County, a jurisdiction of 1.1 million residents and several large government contractors.

County voters also approved a $310 million bond to finance new school construction and a $151 million bond to go toward building or renovating police stations, firehouses and other public-safety facilities.

Come January, Democrats will hold eight seats on the Board of Supervisors, one more than before the election.

Bulova (D) handily won her reelection bid, with 60 percent of the votes cast compared with 34 percent for her Republican opponent, Arthur Purves, according to unofficial returns. Independent candidate Glenda Gail Parker had 6 percent.

In the election to replace outgoing Supervisor Michael R. Frey (R-Sully), School Board member Kathy L. Smith (D) beat John Guevara (R), 52 percent to 48 percent, with all precincts reporting. In Mount Vernon, where Supervisor Gerald W. Hyland (D) is also leaving, School Board member Daniel G. Storck (D) had 57 percent of the votes, and Jane Gandee (R) had 43 percent.

Across the county, the board races were dominated by concerns over an economic slump that has forced cuts to public schools, libraries and other services.

Fairfax has been hit hard by federal cuts to defense spending, leading to budget deficits that have made it more difficult to meet the demands of a growing school system that currently enrolls nearly 187,000 students. Those needs, and a strong anti-tax sentiment among many residents, have sparked sometimes-bitter budget battles between the Board of Supervisors and school officials.

The county is also trying to revive older neighborhoods that are deteriorating and improve the ­often-nightmarish traffic on some local roads. In addition, the county seeks to implement potentially expensive reforms at a police department that has been immersed in controversy over a police officer’s fatal shooting in 2013 of John Geer, who was unarmed.

Those themes helped fuel heated exchanges in some of the county’s more competitive races.

In the Dranesville District, incumbent John W. Foust (D) and Jennifer Chronis (R) clashed over the county’s fiscal challenges. Foust had 54 percent of the votes, while Chronis had 46 percent.

In that race, Chronis blamed Foust for the rising residential property tax rates in the county, which she said are driving some homeowners out of Fairfax.

Foust argued that property tax rates have been stable in recent years and added that he’s been working to diversify the county’s contracting-dependent economy.

Their race intensified over recent controversy surrounding a McLean gun store that opened near an elementary school.

Foust, who joined a protest against the store when it opened, accused Chronis of disregarding parents’ concerns on the issue. Chronis said she wanted to broker a peaceful resolution to the controversy and attacked Foust for mailing out a flier depicting a ­bullet-pocked traffic sign featuring a child running while saying Chronis backs the store’s location.

“Foust has been a very hard worker,” Chuck Mudd said after casting a vote for the incumbent. “He really gets involved.

In the Sully District race, the candidates argued over how to fix traffic problems in that increasingly dense portion of western Fairfax. Smith promised to be a fierce advocate for state transportation dollars to be spent in her district, and called for further investigating the idea of extending Metrorail’s Orange Line.

Guevara said there should be more ­public-private partnerships to deal with traffic problems and called for faster county responses to daily traffic headaches. Along those lines, his campaign launched a Web site, www.sullystreets.com, so residents could report pressing road problems.

Smith was among three candidates for supervisor who were current or former School Board members, a dynamic in the elections that has the potential to alter budget negotiations between the County Board and school officials. The other two were Storck, of the Mount Vernon District, who won his race, and former school board member Janet Oleszek in the Braddock District, who lost hers.

Storck called for transferring more county funds to schools to ease classroom overcrowding in his district. Gandee, a member of the local Chamber of Commerce, said wasteful spending should first be addressed in the school system — with an audit.The candidates both promised to work toward relieving traffic congestion along the Route 1 corridor and bringing in more new businesses to struggling parts of the district.

In the Braddock District, Oleszek (D) advocated for allowing voters to decide on whether a tax on restaurant meals should be instituted to raise more funds for county schools. Her Republican opponent, John Cook, had 52 percent of the vote, and Oleszek had 46 percent with all precincts reporting. Independent candidate Carey Campbell had 2 percent.

Cook, who was first elected in 2011, argued against more taxes but said more county funds should be allocated toward new school construction. He also campaigned for better services for residents with mental health problems — a problem that drew public scrutiny this year when Natasha McKenna, who had a history of mental illness, died after being Tasered four times in the county jail.

In the Mason District, Supervisor Penelope A. Gross (D) won a sixth term over Mollie Loeffler, an independent who mounted a strong effort against her. Gross had 58 precent of the vote, and Loeffler had 42 percent.

In the Springfield District, Supervisor Pat Herrity (R) won easily over independent Corazon Foley for his third term in office, capturing 81 percent of the vote. Supervisors Jeff C. McKay (D-Lee), Catherine M. Hudgins (D-Hunter Mill) and Linda Q. Smyth (D-Providence) ran unopposed.

Winners of the School Board elections were Ilryong Moon, Ryan McElveen, Jeanette Hough, Megan McLaughlin, Pat Hynes, Jane K. Strauss, Tamara Derenak Kaufax, Sandra Evans, Karen Corbett Sanders, Dalia Palchik and Elizabeth Schultz. Thomas Wilson was leading Karen Keys-Gamarra by 181 votes in the board’s Sully District race, but county officials said they will recheck the vote tallies Wednesday.