School board races are often predictable affairs, pivoting on long-standing issues in education — boosting teacher pay, closing achievement gaps and reducing overcrowding.

But, this being 2019, the campaigns for school board in Fairfax County took on another dimension. The usually low-profile contests — which are nominally nonpartisan — became bitterly partisan, with Republicans lambasting Democrats for policies the GOP said amounted to social engineering. Democrats accused Republicans of manufacturing problems to foster panic.

But how would voters in the Virginia suburbs respond?

Tuesday’s election delivered an answer: Democratic-endorsed candidates swept all 12 seats on the school board. It was a decisive victory that, in the eyes of newly elected school board members and their supporters, represented a categorical rejection of what they viewed as a vitriolic campaign by Republican-endorsed candidates that relied on spreading fear and misinformation.

“Voters soundly rejected the fearmongering,” said Karl Frisch, who was elected to represent the Providence District on the board. “People did not fall for the lies.”

Timothy Hannigan, chairman of the Fairfax County Republican Committee, rebuffed Democrats’ claims about fearmongering. He said the Republican Party must do more to recruit conservative voters and lamented the loss of Republican perspectives on the board.

“We feel that some of the top-down ideological Democrat proposals are veering away from a focus on student achievement,” Hannigan said.

Voters ousted the two Republican-endorsed school board members, including Elizabeth L. Schultz, an outspoken conservative who has sparred with colleagues over curriculum that includes lessons on gender identity and who generated outrage in Fairfax County over her support for President Trump.

They elected Frisch, the panel’s first openly gay member. They elevated 24-year-old Abrar E. Omeish, the youngest-ever school board member and the first Muslim. It is the first time every seat on the school board will be held by a candidate endorsed by the modern Democratic Party, according to the Fairfax County Democratic Committee.

The incoming school board is younger, more diverse and, some newly elected members say, more representative of Fairfax County.

“The county’s population is evolving, just as our school board is,” said Frisch, who was inspired to run for office by his partner, an educator.

Omeish, a Fairfax native, ran on a platform that focused on highlighting the voices of young people and members of underrepresented communities. A majority of the students in the district are students of color, while the school board and teaching ranks remain mostly white.

During the campaign, Omeish was the target of Islamaphobic attacks online. She was accused of belonging to the Taliban. The attacks, she said, will make her a stronger school board member, one who can better relate to students who endure similar episodes.

“It would have been naive of me to run thinking I wouldn’t have faced it,” said Omeish, who won an at-large seat.

In some parts of the county, political winds have shifted rapidly. Four years ago, the seat Frisch won was held by a Republican. In the Sully District, Stella G. Pekarsky trounced Republican-endorsed incumbent Thomas A. Wilson by 17 percentage points.

Their success in Fairfax County corresponded with a broader Democratic takeover in Virginia in which the party flipped both chambers in the statehouse to seize full control of state government.

Dan Lagana, chairman of the Fairfax County Democratic Committee, said that since 2015, Republican-backed candidates have focused on social issues that have not held sway with voters, such as the school board’s decision to expand protections for transgender students.

More recently, Republican-backed candidates pushed back against One Fairfax, a measure officials passed last year that ensures the county applies racial and social equity as a factor when making decisions. They also asserted their Democratic-backed opponents wanted to bus students across the county to balance schools by race and income.

Candidates backed by the Democratic Party flatly rejected those claims. Karen Corbett Sanders, the Democratic-endorsed school board chairwoman, decried the “inflammatory rhetoric” that circulated.

“It was unbelievable in the level of vitriol and false information that was put out,” said Corbett Sanders, who easily won reelection.

One Republican-endorsed candidate, Vinson Xavier Palathingal, disagreed with Democrats’ assessment that the election was a sign of support for One Fairfax and other liberal policies. Palathingal captured the fewest votes of any of the six candidates who ran for an at-large seat.

Instead, he said he feels widespread anti-Trump sentiment cost him and other Republican-backed candidates more moderate suburban voters.

Palathingal, who said he twice voted for President Barack Obama but defected from the Democratic Party after becoming disillusioned by its policies, said his unsuccessful run for office strengthened his political convictions.

“I’m going to be a much more strong Republican than I was before,” he said.