The reelection of a lifelong Democrat who has held public office in deep-blue Arlington County for almost 20 years should be a slam-dunk.

But Libby Garvey, the chair of the majority-Democratic County Board, is facing a tough challenger in the June 14 primary, one who has outperformed her in fundraising and endorsements from leading members of her party.

Over the past four years, Garvey has become a lightning rod for criticism because of her willingness to break with her party and her tendency to question long-standing county government practices. Last week, she was forced to retreat on one of her signature initiatives, creating a “blue-ribbon panel” to advise the board on setting strategic priorities.

“Democratic Party members have worked hard to elect Democrats because of our shared values,” said Reid Goldstein, an Arlington School Board member. “She decided to go off on her own. . . . People remember.”

Veteran politicians in Arlington say it is exceedingly rare for a Democratic incumbent to face such vigorous primary opposition, but Garvey, 65, says she is fine with the role of pariah.

Libby Garvey is chairman of the Arlington County Board (Nadya Lutz/Nadya Lutz)

“For my entire career, I’ve seen things that need to be done,” she said. “And if they ruffle feathers, so be it.”

Erik Gutshall, Garvey’s challenger, has attacked Garvey’s leadership skills and fiscal conservatism, blaming her for much of the political animosity that has dominated the board over the past four years.

He said he decided to run because “everything I’ve participated in over the last 20 years in Arlington seemed to me to be in jeopardy. I see her as a fundamental obstacle who is not taking us in the right direction to solve the problems we have to solve in the future.”

Backed by almost $52,000 in contributions in the first quarter of the year, the 46-year-old planning-board member has lined up endorsements from 16 current and former elected officials. Garvey has just four — and only one of those, commonwealth attorney Theo Stamos, is still in office. She raised $34,600 through the end of March this year, according to the Virginia Public Access Project, to add to $27,566 in leftover funds from her 2012 campaign.

Her lone backer on the County Board is John Vihstadt, a longtime Republican who ran as an independent and has teamed with Garvey to stop projects they deem overly expensive, including the long-planned Columbia Pike streetcar.

Vihstadt says that Garvey has earned reelection, citing her “creative, evenhanded and productive chairmanship,” and her efforts at greater accountability and streamlined business practices.

“Fundamentally, there’s a group of established figures who have never forgiven her for opposing the streetcar or supporting me,” Vihstadt said, drawing a distinction between party activists and average citizens. “Voters I’ve spoken with don’t want to reverse course to the cozy, back-scratching days of old.”

Virginia voters do not register by party, so the primary is open to all. With the Garvey-Gutshall race the only contest on the ballot, turnout is expected to be low, even though the winner will be the overwhelming favorite to win the seat in November.

“If Democrats go out and vote, this is going to be a really, really close election,” said Jarrod Nagurka, a party activist who supports Gutshall.

He said he is worried about voters who would normally vote Republican turning out to support Garvey. Her base includes many independent and Republican-leaning voters who think previous boards were not careful guardians of taxpayer money.

The rancor between Garvey and establishment Democrats began shortly after she won a squeaker of a special election to fill an open seat in spring 2012. At the time, community opposition to the streetcar had begun to percolate.

Garvey dithered publicly on the issue, abstaining from a key vote that summer. But during her general election campaign, she came out against the streetcar.

After winning a full term, she accused board member Chris Zimmerman (D), the board’s strongest streetcar proponent, of a potential conflict of interest, because he was a consultant for a Canadian company that had been involved in the streetcar plans. Zimmerman strongly denied any conflict, saying his work with the group was limited to other projects. The board’s attorney agreed, and the board publicly rebuked Garvey.

In 2014, Zimmerman resigned from the board and Garvey publicly endorsed and contributed money to Vihstadt as he campaigned for the open seat.

Local party activists were furious that she was working against the Democratic nominee. Under pressure, Garvey resigned from the party’s leadership committee. She was reinstated the following year, but says she cannot promise to support all Democrats in the future. “I put the good of the community before the good of the party,” she said in an interview.

Vihstadt’s election, after 15 years of an all-Democratic board, triggered such upheaval that the County Board pulled the plug on the streetcar plan. “Do I feel vindicated?” Garvey said at the time. “It was John’s election, but we were reflecting the views of many in Arlington.”

Garvey’s recent blue-ribbon-panel proposal was unveiled at a Tuesday afternoon meeting, a time when the board usually hands out proclamations. Although she has pushed for earlier public notification of meeting agendas, the proposal was not listed in advance — an unusual omission that was immediately noticed by her critics.

Vice Chairman Jay Fisette (D), a Gutshall supporter, questioned the need for the panel but ultimately voted for it, as did the rest of the board. That brought a torrent of complaints from organizations and citizens who called the panel an attempt to bypass Arlington’s tradition of extensive community input.

The vote to create the panel “was taken with almost no advance notice or opportunity for public comment,” said a letter from Virginians Organized for Interfaith Community Engagement. “The panel is duplicative; the charge is murky and invests far too much power in 6 people.”

Garvey backed off last week, calling the lack of notice “an oversight” and promising to more clearly define what she sought to accomplish with the panel before the issue returns to the board in July. “It seemed like a quick way to get some advice,” she said.

Other initiatives have been more successful. Her efforts to hire an inspector general or independent auditor began to bear fruit last year, when the board agreed to budget money for an auditor who reports only to them, rather than through the county manager.

But she angered school officials and some parents by touting a one-time infusion of $1.1 million in school funding this spring as evidence of the county board’s deep commitment to funding public education.

Critics point out that the $1.1 million cannot be used to hire permanent staff or create ongoing programs. By conflating the two, they say, Garvey made it seem as though schools were being overfunded — a perception that school board member James Lander called “blatantly misleading.”

Garvey agreed to remove a reference to the extra money as “one-time and ongoing funding above the school board’s funding request” from the official county statement on the school system’s budget appropriation. But she’s continued to talk about it that way in campaign appearances.